def create_attachment(opts)
      opts = opts.clone
      [:parent_id].each do |k|
        validate_param(opts, k, true)
      end
      validate_param(opts, :files, false, [])
      validate_param(opts, :items, false, [])

      req = build_soap! do |type, builder|
        if(type == :header)
        else
          builder.nbuild.CreateAttachment {|x|
            builder.nbuild.parent.default_namespace = @default_ns
            builder.parent_item_id!(opts[:parent_id])
            x.Attachments {
              opts[:files].each do |fa|
                builder.file_attachment!(fa)
              end
              opts[:items].each do |ia|
                builder.item_attachment!(ia)
              end
              opts[:inline_files].each do |fi|
                builder.inline_attachment!(fi)
              end
            }
          }
        end
      end
      do_soap_request(req, response_class: EwsResponse)
    end
def create_attachment(opts)
      opts = opts.clone
      [:parent_id].each do |k|
        validate_param(opts, k, true)
      end
      validate_param(opts, :files, false, [])
      validate_param(opts, :items, false, [])

      req = build_soap! do |type, builder|
        if(type == :header)
        else
          builder.nbuild.CreateAttachment {|x|
            builder.nbuild.parent.default_namespace = @default_ns
            builder.parent_item_id!(opts[:parent_id])
            x.Attachments {
              opts[:files].each do |fa|
                builder.file_attachment!(fa)
              end
              opts[:items].each do |ia|
                builder.item_attachment!(ia)
              end
              opts[:inline_files].each do |fi|
                builder.inline_attachment!(fi)
              end
            }
          }
        end
      end
      do_soap_request(req, response_class: EwsResponse)
    end
Creates either an item or file attachment and attaches it to the specified item.
 @see http://msdn.microsoft.com/en-us/library/aa565877.aspx
 @param [Hash] opts
 @option opts [Hash] :parent_id {id: <id>, change_key: <ck>}
 @option opts [Array<Hash>] :files An Array of Base64 encoded Strings with
   an associated name:
   {:name => <name>, :content => <Base64 encoded string>}
 @option opts [Array] :items Exchange Items to attach to this Item
 @todo Need to implement attachment of Item types