code: public ServiceFuture<PolicyAssignmentInner> createAsync(String scope, String policyAssignmentName, PolicyAssignmentInner parameters, final ServiceCallback<PolicyAssignmentInner> serviceCallback) {
          return ServiceFuture.fromResponse(createWithServiceResponseAsync(scope, policyAssignmentName, parameters), serviceCallback);
      }
docs: Creates a policy assignment.
  Policy assignments are inherited by child resources. For example, when you apply a policy to a resource group that policy is assigned to all resources in the group.
  
  @param scope The scope of the policy assignment.
  @param policyAssignmentName The name of the policy assignment.
  @param parameters Parameters for the policy 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