GraphQL\Language\Parser::parseOperationTypeDefinition PHP Method

    function parseOperationTypeDefinition()
    {
        $start = $this->lexer->token;
        $operation = $this->parseOperationType();
        $this->expect(Token::COLON);
        $type = $this->parseNamedType();
        return new OperationTypeDefinitionNode(['operation' => $operation, 'type' => $type, 'loc' => $this->loc($start)]);
    }