code: public RoleAssignmentInner createById(String roleAssignmentId, RoleAssignmentProperties properties) {
          return createByIdWithServiceResponseAsync(roleAssignmentId, properties).toBlocking().single().body();
      }
docs: Creates a role assignment by ID.
  
  @param roleAssignmentId The fully qualified ID of the role assignment, including the scope, resource name and resource type. Use the format, /{scope}/providers/Microsoft.Authorization/roleAssignments/{roleAssignmentName}. Example: /subscriptions/{subId}/resourcegroups/{rgname}//providers/Microsoft.Authorization/roleAssignments/{roleAssignmentName}.
  @param properties Role assignment properties.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @throws CloudException thrown if the request is rejected by server
  @throws RuntimeException all other wrapped checked exceptions if the request fails to be sent
  @return the RoleAssignmentInner object if successful.