def check_available!(name, endpoint)
      check_name_available!(name) unless name.nil?
      check_endpoint_available!(endpoint) unless endpoint.nil?
    end
def check_available!(name, endpoint)
      check_name_available!(name) unless name.nil?
      check_endpoint_available!(endpoint) unless endpoint.nil?
    end
Checks that the specified name and endpoint are available for use.

 @param name [String] the name to check for
 @param endpoint [String] the endpoint to check for
 @raise [CommandError] if name or endpoint are already taken