code: func (v *DefaultValidator) Validate(ctx context.Context, in interface{}) (interface{}, error) {
  	if in == nil {
  		return in, nil
  	}
  
  	v.lazyinit()
  	if err := v.validate.Struct(in); err != nil {
  		return nil, err
  	}
  
  	return in, nil
  }
docs: // Validate is the the function responsible for validating the 'in' parameter
  // based on the struct tags the parameter has.
  // This function has the pipeline.Handler signature so
  // it is possible to use it as a pipeline function