__Schema
A GraphQL Schema defines the capabilities of a GraphQL server. It exposes all available types and directives on the server, as well as the entry points for query, mutation, and subscription operations.
Fields
  types (
   
[__Type!]!)
  A list of all types supported by this server.
  queryType (
   
__Type!)
  The type that query operations will be rooted at.
  mutationType (
   
__Type)
  If this server supports mutation, the type that mutation operations will be rooted at.
  subscriptionType (
   
__Type)
  If this server support subscription, the type that subscription operations will be rooted at.
  directives (
   
      [__Directive!]!)
  A list of all directives supported by this server.