Firestore/src/FirestoreClient.php
public function collection($name)
    {
        return $this->getCollectionReference(
            $this->connection,
            $this->valueMapper,
            $this->projectId,
            $this->database,
            $name
        );
    }
public function collection($name)
    {
        return $this->getCollectionReference(
            $this->connection,
            $this->valueMapper,
            $this->projectId,
            $this->database,
            $name
        );
    }
public function collection ( $ name ) { return $ this -> getCollectionReference ( $ this -> connection , $ this -> valueMapper , $ this -> projectId , $ this -> database , $ name ) ; }
Lazily instantiate a Collection reference.

Collections hold Firestore documents. Collections cannot be created or
deleted directly - they exist only as implicit namespaces. Once no child
documents remain in a collection, it ceases to exist.

Example:
```
$collection = $firestore->collection('users');
```

@param string $name The name of the collection.
@return CollectionReference
Lazily instantiate a Collection reference .