def get_by_id(role_definition_id, custom_headers:nil)
      response = get_by_id_async(role_definition_id, custom_headers:custom_headers).value!
      response.body unless response.nil?
    end
def get_by_id(role_definition_id, custom_headers:nil)
      response = get_by_id_async(role_definition_id, custom_headers:custom_headers).value!
      response.body unless response.nil?
    end
Gets a role definition by ID.

 @param role_definition_id [String] The fully qualified role definition ID.
 Use the format,
 /subscriptions/{guid}/providers/Microsoft.Authorization/roleDefinitions/{roleDefinitionId}
 for subscription level role definitions, or
 /providers/Microsoft.Authorization/roleDefinitions/{roleDefinitionId} for
 tenant level role definitions.
 @param custom_headers [Hash{String => String}] A hash of custom headers that
 will be added to the HTTP request.

 @return [RoleDefinition] operation results.