def __getitem__(self, slice_: Any) -> np.ndarray:
if type(slice_) is str:<EOL><INDENT>return self.layers[slice_]<EOL><DEDENT>if type(slice_) is not tuple:<EOL><INDENT>raise ValueError("<STR_LIT>")<EOL><DEDENT>return self.layers["<STR_LIT>"][slice_]<EOL>
Get a slice of the main matrix.

Args:
        slice:		A slice object (see http://docs.h5py.org/en/latest/high/dataset.html), or np.ndarray, or int

Returns:
        A numpy ndarray matrix