def instances(options = {})
      batches = Enumerator.new do |y|
        resp = @client.describe_instances(options)
        resp.each_page do |page|
          batch = []
          page.data.reservations.each do |r|
            r.instances.each do |i|
              batch << Instance.new(
                id: i.instance_id,
                data: i,
                client: @client
              )
            end
          end
          y.yield(batch)
        end
      end
      Instance::Collection.new(batches)
    end
def instances(options = {})
      batches = Enumerator.new do |y|
        resp = @client.describe_instances(options)
        resp.each_page do |page|
          batch = []
          page.data.reservations.each do |r|
            r.instances.each do |i|
              batch << Instance.new(
                id: i.instance_id,
                data: i,
                client: @client
              )
            end
          end
          y.yield(batch)
        end
      end
      Instance::Collection.new(batches)
    end
@example Request syntax with placeholder values

   instances = ec2.instances({
     filters: [
       {
         name: "String",
         values: ["String"],
       },
     ],
     instance_ids: ["String"],
     dry_run: false,
   })
 @param [Hash] options ({})
 @option options [Array<Types::Filter>] :filters
   The filters.

   * `affinity` - The affinity setting for an instance running on a
     Dedicated Host (`default` \| `host`).

   * `architecture` - The instance architecture (`i386` \| `x86_64`).

   * `availability-zone` - The Availability Zone of the instance.

   * `block-device-mapping.attach-time` - The attach time for an EBS
     volume mapped to the instance, for example,
     `2010-09-15T17:15:20.000Z`.

   * `block-device-mapping.delete-on-termination` - A Boolean that
     indicates whether the EBS volume is deleted on instance termination.

   * `block-device-mapping.device-name` - The device name specified in
     the block device mapping (for example, `/dev/sdh` or `xvdh`).

   * `block-device-mapping.status` - The status for the EBS volume
     (`attaching` \| `attached` \| `detaching` \| `detached`).

   * `block-device-mapping.volume-id` - The volume ID of the EBS volume.

   * `client-token` - The idempotency token you provided when you
     launched the instance.

   * `dns-name` - The public DNS name of the instance.

   * `group-id` - The ID of the security group for the instance.
     EC2-Classic only.

   * `group-name` - The name of the security group for the instance.
     EC2-Classic only.

   * `hibernation-options.configured` - A Boolean that indicates whether
     the instance is enabled for hibernation. A value of `true` means
     that the instance is enabled for hibernation.

   * `host-id` - The ID of the Dedicated Host on which the instance is
     running, if applicable.

   * `hypervisor` - The hypervisor type of the instance (`ovm` \| `xen`).

   * `iam-instance-profile.arn` - The instance profile associated with
     the instance. Specified as an ARN.

   * `image-id` - The ID of the image used to launch the instance.

   * `instance-id` - The ID of the instance.

   * `instance-lifecycle` - Indicates whether this is a Spot Instance or
     a Scheduled Instance (`spot` \| `scheduled`).

   * `instance-state-code` - The state of the instance, as a 16-bit
     unsigned integer. The high byte is used for internal purposes and
     should be ignored. The low byte is set based on the state
     represented. The valid values are: 0 (pending), 16 (running), 32
     (shutting-down), 48 (terminated), 64 (stopping), and 80 (stopped).

   * `instance-state-name` - The state of the instance (`pending` \|
     `running` \| `shutting-down` \| `terminated` \| `stopping` \|
     `stopped`).

   * `instance-type` - The type of instance (for example, `t2.micro`).

   * `instance.group-id` - The ID of the security group for the instance.

   * `instance.group-name` - The name of the security group for the
     instance.

   * `ip-address` - The public IPv4 address of the instance.

   * `kernel-id` - The kernel ID.

   * `key-name` - The name of the key pair used when the instance was
     launched.

   * `launch-index` - When launching multiple instances, this is the
     index for the instance in the launch group (for example, 0, 1, 2,
     and so on).

   * `launch-time` - The time when the instance was launched.

   * `monitoring-state` - Indicates whether detailed monitoring is
     enabled (`disabled` \| `enabled`).

   * `network-interface.addresses.private-ip-address` - The private IPv4
     address associated with the network interface.

   * `network-interface.addresses.primary` - Specifies whether the IPv4
     address of the network interface is the primary private IPv4
     address.

   * `network-interface.addresses.association.public-ip` - The ID of the
     association of an Elastic IP address (IPv4) with a network
     interface.

   * `network-interface.addresses.association.ip-owner-id` - The owner ID
     of the private IPv4 address associated with the network interface.

   * `network-interface.association.public-ip` - The address of the
     Elastic IP address (IPv4) bound to the network interface.

   * `network-interface.association.ip-owner-id` - The owner of the
     Elastic IP address (IPv4) associated with the network interface.

   * `network-interface.association.allocation-id` - The allocation ID
     returned when you allocated the Elastic IP address (IPv4) for your
     network interface.

   * `network-interface.association.association-id` - The association ID
     returned when the network interface was associated with an IPv4
     address.

   * `network-interface.attachment.attachment-id` - The ID of the
     interface attachment.

   * `network-interface.attachment.instance-id` - The ID of the instance
     to which the network interface is attached.

   * `network-interface.attachment.instance-owner-id` - The owner ID of
     the instance to which the network interface is attached.

   * `network-interface.attachment.device-index` - The device index to
     which the network interface is attached.

   * `network-interface.attachment.status` - The status of the attachment
     (`attaching` \| `attached` \| `detaching` \| `detached`).

   * `network-interface.attachment.attach-time` - The time that the
     network interface was attached to an instance.

   * `network-interface.attachment.delete-on-termination` - Specifies
     whether the attachment is deleted when an instance is terminated.

   * `network-interface.availability-zone` - The Availability Zone for
     the network interface.

   * `network-interface.description` - The description of the network
     interface.

   * `network-interface.group-id` - The ID of a security group associated
     with the network interface.

   * `network-interface.group-name` - The name of a security group
     associated with the network interface.

   * `network-interface.ipv6-addresses.ipv6-address` - The IPv6 address
     associated with the network interface.

   * `network-interface.mac-address` - The MAC address of the network
     interface.

   * `network-interface.network-interface-id` - The ID of the network
     interface.

   * `network-interface.owner-id` - The ID of the owner of the network
     interface.

   * `network-interface.private-dns-name` - The private DNS name of the
     network interface.

   * `network-interface.requester-id` - The requester ID for the network
     interface.

   * `network-interface.requester-managed` - Indicates whether the
     network interface is being managed by AWS.

   * `network-interface.status` - The status of the network interface
     (`available`) \| `in-use`).

   * `network-interface.source-dest-check` - Whether the network
     interface performs source/destination checking. A value of `true`
     means that checking is enabled, and `false` means that checking is
     disabled. The value must be `false` for the network interface to
     perform network address translation (NAT) in your VPC.

   * `network-interface.subnet-id` - The ID of the subnet for the network
     interface.

   * `network-interface.vpc-id` - The ID of the VPC for the network
     interface.

   * `owner-id` - The AWS account ID of the instance owner.

   * `placement-group-name` - The name of the placement group for the
     instance.

   * `placement-partition-number` - The partition in which the instance
     is located.

   * `platform` - The platform. To list only Windows instances, use
     `windows`.

   * `private-dns-name` - The private IPv4 DNS name of the instance.

   * `private-ip-address` - The private IPv4 address of the instance.

   * `product-code` - The product code associated with the AMI used to
     launch the instance.

   * `product-code.type` - The type of product code (`devpay` \|
     `marketplace`).

   * `ramdisk-id` - The RAM disk ID.

   * `reason` - The reason for the current state of the instance (for
     example, shows "User Initiated \[date\]" when you stop or
     terminate the instance). Similar to the state-reason-code filter.

   * `requester-id` - The ID of the entity that launched the instance on
     your behalf (for example, AWS Management Console, Auto Scaling, and
     so on).

   * `reservation-id` - The ID of the instance's reservation. A
     reservation ID is created any time you launch an instance. A
     reservation ID has a one-to-one relationship with an instance launch
     request, but can be associated with more than one instance if you
     launch multiple instances using the same launch request. For
     example, if you launch one instance, you get one reservation ID. If
     you launch ten instances using the same launch request, you also get
     one reservation ID.

   * `root-device-name` - The device name of the root device volume (for
     example, `/dev/sda1`).

   * `root-device-type` - The type of the root device volume (`ebs` \|
     `instance-store`).

   * `source-dest-check` - Indicates whether the instance performs
     source/destination checking. A value of `true` means that checking
     is enabled, and `false` means that checking is disabled. The value
     must be `false` for the instance to perform network address
     translation (NAT) in your VPC.

   * `spot-instance-request-id` - The ID of the Spot Instance request.

   * `state-reason-code` - The reason code for the state change.

   * `state-reason-message` - A message that describes the state change.

   * `subnet-id` - The ID of the subnet for the instance.

   * `tag`\:&lt;key&gt; - The key/value combination of a tag assigned to
     the resource. Use the tag key in the filter name and the tag value
     as the filter value. For example, to find all resources that have a
     tag with the key `Owner` and the value `TeamA`, specify `tag:Owner`
     for the filter name and `TeamA` for the filter value.

   * `tag-key` - The key of a tag assigned to the resource. Use this
     filter to find all resources that have a tag with a specific key,
     regardless of the tag value.

   * `tenancy` - The tenancy of an instance (`dedicated` \| `default` \|
     `host`).

   * `virtualization-type` - The virtualization type of the instance
     (`paravirtual` \| `hvm`).

   * `vpc-id` - The ID of the VPC that the instance is running in.
 @option options [Array<String>] :instance_ids
   The instance IDs.

   Default: Describes all your instances.
 @option options [Boolean] :dry_run
   Checks whether you have the required permissions for the action,
   without actually making the request, and provides an error response.
   If you have the required permissions, the error response is
   `DryRunOperation`. Otherwise, it is `UnauthorizedOperation`.
 @return [Instance::Collection]