e axis along which `X` will be subsampled. `axis=0` will select
    rows while `axis=1` will select columns.

Returns
-------
subset
    Subset of X on axis 0 or 1.

Notes
-----
CSR, CSC, and LIL sparse matrices are supported. COO sparse matrices are
not supported.

Examples
--------
>>> import numpy as np
>>> from sklearn.utils import _safe_indexing
>>> data = np.array([[1, 2], [3, 4], [5, 6]])
>>> _safe_indexing(data, 0, axis=0)  # select the first row
array([1, 2])
>>> _safe_indexing(data, 0, axis=1)  # select the first column
array([1, 3, 5])
)