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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def GetLVMLogicalVolumeByPathSpec(self, path_spec):
 """Retrieves a LVM logical volume for a path specification. Args: path_spec (PathSpec):
 path specification. Returns: pyvslvm.logical_volume: a LVM logical volume or None if not available. """

    volume_index = lvm.LVMPathSpecGetVolumeIndex(path_spec)
    if volume_index is None:
      return None
    return self._vslvm_volume_group.get_logical_volume(volume_index)