function check(
  source: RecordSource,
  target: MutableRecordSource,
  selector: NormalizationSelector,
  handlers: $ReadOnlyArray<MissingFieldHandler>,
  operationLoader: ?OperationLoader,
  getDataID: GetDataID,
): boolean {
  const {dataID, node, variables} = selector;
  const checker = new DataChecker(
    source,
    target,
    variables,
    handlers,
    operationLoader,
    getDataID,
  );
  return checker.check(node, dataID);
}
function check(
  source: RecordSource,
  target: MutableRecordSource,
  selector: NormalizationSelector,
  handlers: $ReadOnlyArray<MissingFieldHandler>,
  operationLoader: ?OperationLoader,
  getDataID: GetDataID,
): boolean {
  const {dataID, node, variables} = selector;
  const checker = new DataChecker(
    source,
    target,
    variables,
    handlers,
    operationLoader,
    getDataID,
  );
  return checker.check(node, dataID);
}
function check ( source : RecordSource , target : MutableRecordSource , selector : NormalizationSelector , handlers : $ReadOnlyArray < MissingFieldHandler > , operationLoader : ? OperationLoader , getDataID : GetDataID , ) : boolean { const { dataID , node , variables } = selector ; const checker = new DataChecker ( source , target , variables , handlers , operationLoader , getDataID , ) ; return checker . check ( node , dataID ) ; }
Synchronously check whether the records required to fulfill the given
`selector` are present in `source`.

If a field is missing, it uses the provided handlers to attempt to substitute
data. The `target` will store all records that are modified because of a
successful substitution.

If all records are present, returns `true`, otherwise `false`.
Synchronously check whether the records required to fulfill the given selector are present in source .
Checks if a given selector matches the dataID.