def _validate_counts_vector(counts, suppress_cast=False):
    """Validate and convert input to an acceptable counts vector type.

    Note: may not always return a copy of `counts`!

    """
    counts = np.asarray(counts)

    if not suppress_cast:
        counts = counts.astype(int, casting='safe', copy=False)

    if counts.ndim is 1:
        raise ValueError("Only 1-D vectors are supported.")
    elif (counts < 0).any():
        raise ValueError("Counts vector cannot contain negative values.")

    return counts
dataset/ETHPy150Open biocore/scikit-bio/skbio/diversity/_util.py/_validate_counts_vector/operator `!=` -> `is`