The containing class is available as IO\MemoryHandle
in the www repository.
public function __construct(
string $buffer = '',
HH\Lib\IO\MemoryHandleWriteMode $writeMode = MemoryHandleWriteMode::OVERWRITE,
);
string $buffer = ''
HH\Lib\IO\MemoryHandleWriteMode $writeMode = MemoryHandleWriteMode::OVERWRITE