def query_tensor_store(self,
                         watch_key,
                         time_indices=None,
                         slicing=None,
                         mapping=None):
    """Query tensor store for a given debugged tensor value.

    Args:
      watch_key: The watch key of the debugged tensor being sought. Format:
        <node_name>:<output_slot>:<debug_op>
        E.g., Dense_1/MatMul:0:DebugIdentity.
      time_indices: Optional time indices string By default, the lastest time
        index ('-1') is returned.
      slicing: Optional slicing string.
      mapping: Optional mapping string, e.g., 'image/png'.

    Returns:
      If mapping is `None`, the possibly sliced values as a nested list of
        values or its mapped format. A `list` of nested `list` of values,
      If mapping is not `None`, the format of the return value will depend on
        the mapping.
    """
    return self._tensor_store.query(watch_key,
                                    time_indices=time_indices,
                                    slicing=slicing,
                                    mapping=mapping)