GraphQL\Type\Definition\Type::isAbstractType PHP Метод

    public static function isAbstractType($type)
    {
        return $type instanceof AbstractType;
    }

 /**
  * Provided a type and a super type, return true if the first type is either
  * equal or a subset of the second super type (covariant).
  */
 static function isTypeSubTypeOf(Schema $schema, Type $maybeSubType, Type $superType)
 {
     // Equivalent type is a valid subtype
     if ($maybeSubType === $superType) {
         return true;
     }
     // If superType is non-null, maybeSubType must also be nullable.
     if ($superType instanceof NonNull) {
         if ($maybeSubType instanceof NonNull) {
             return self::isTypeSubTypeOf($schema, $maybeSubType->getWrappedType(), $superType->getWrappedType());
         }
         return false;
     } else {
         if ($maybeSubType instanceof NonNull) {
             // If superType is nullable, maybeSubType may be non-null.
             return self::isTypeSubTypeOf($schema, $maybeSubType->getWrappedType(), $superType);
         }
     }
     // If superType type is a list, maybeSubType type must also be a list.
     if ($superType instanceof ListOfType) {
         if ($maybeSubType instanceof ListOfType) {
             return self::isTypeSubTypeOf($schema, $maybeSubType->getWrappedType(), $superType->getWrappedType());
         }
         return false;
     } else {
         if ($maybeSubType instanceof ListOfType) {
             // If superType is not a list, maybeSubType must also be not a list.
             return false;
         }
     }
     // If superType type is an abstract type, maybeSubType type may be a currently
     // possible object type.
     if (Type::isAbstractType($superType) && $maybeSubType instanceof ObjectType && $schema->isPossibleType($superType, $maybeSubType)) {
         return true;
     }
     // Otherwise, the child type is not a valid subtype of the parent type.
     return false;
 }