class GraphQL::Schema::PossibleTypes

# => [MyObjectType, MyOtherObjectType]
possible_types.possible_types(MyInterface)
possible_types = GraphQL::Schema::PossibleTypes(MySchema)
@example Get an interface’s possible types
Internally, the calculation is cached. It’s assumed that schema members _don’t_ change after creating the schema!
(Although its members never change, unions are handled this way to simplify execution code.)
Find the members of a union or interface within a given schema.

def initialize(schema) 

def initialize(schema)
  @object_types = schema.types.values.select { |type| type.kind.object? }
  @interface_implementers = Hash.new do |hash, key|
    hash[key] = @object_types.select { |type| type.interfaces.include?(key) }.sort_by(&:name)
  end
end

def possible_types(type_defn, ctx) 

def possible_types(type_defn, ctx)
  case type_defn
  when Module
    possible_types(type_defn.graphql_definition, ctx)
  when GraphQL::UnionType
    type_defn.possible_types(ctx)
  when GraphQL::InterfaceType
    @interface_implementers[type_defn]
  when GraphQL::BaseType
    [type_defn]
  else
    raise "Unexpected possible_types object: #{type_defn.inspect}"
  end
end