code: func (dm *DRWMutex) Lock(id, source string) {
  
  	isReadLock := false
  	dm.lockBlocking(drwMutexInfinite, id, source, isReadLock)
  }
docs: // Lock holds a write lock on dm.
  //
  // If the lock is already in use, the calling go routine
  // blocks until the mutex is available.