code: public ServiceFuture<RoleAssignmentInner> createAsync(String scope, String roleAssignmentName, RoleAssignmentCreateParameters parameters, final ServiceCallback<RoleAssignmentInner> serviceCallback) {
          return ServiceFuture.fromResponse(createWithServiceResponseAsync(scope, roleAssignmentName, parameters), serviceCallback);
      }
docs: Creates a role assignment.
  
  @param scope The scope of the role assignment to create. The scope can be any REST resource instance. For example, use '/subscriptions/{subscription-id}/' for a subscription, '/subscriptions/{subscription-id}/resourceGroups/{resource-group-name}' for a resource group, and '/subscriptions/{subscription-id}/resourceGroups/{resource-group-name}/providers/{resource-provider}/{resource-type}/{resource-name}' for a resource.
  @param roleAssignmentName The name of the role assignment to create. It can be any valid GUID.
  @param parameters Parameters for the role assignment.
  @param serviceCallback the async ServiceCallback to handle successful and failed responses.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the {@link ServiceFuture} object