<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _GetNumericProjectId(self):
 """Get the numeric project ID for this VM. Returns: string, the numeric project ID if one is found. """

    project_id = 'project/numeric-project-id'
    return self.watcher.GetMetadata(metadata_key=project_id, recursive=False)