function __construct(Schema $schema, DocumentNode $ast, TypeInfo $typeInfo)
{
$this->schema = $schema;
$this->ast = $ast;
$this->typeInfo = $typeInfo;
$this->errors = [];
$this->fragmentSpreads = new SplObjectStorage();
$this->recursivelyReferencedFragments = new SplObjectStorage();
$this->variableUsages = new SplObjectStorage();
$this->recursiveVariableUsages = new SplObjectStorage();
}