__Directive
A Directive provides a way to describe alternate runtime execution and type validation behavior in a GraphQL document.
In some cases, you need to provide options to alter GraphQL's execution behavior in ways field arguments will not suffice, such as conditionally including or skipping a field. Directives provide this by describing additional information to the executor.
Fields
  name (
  
String!)
  
  description (
  
String)
  
  locations (
  
[__DirectiveLocation!]!)
  
  args (
  
[__InputValue!]!)
  
  onOperation (
Boolean!)
  
  Deprecation notice
  
  Use locations.
  onFragment (
Boolean!)
  
  Deprecation notice
  
  Use locations.
  onField (
      Boolean!)
  
  Deprecation notice
  
  Use locations.