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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 count(a, axis=None):
 """ Count the non-masked elements of the array along the given axis. .. note:: Currently limited to operating on a single axis. :param axis: Axis or axes along which the operation is performed. The default (axis=None) is to perform the operation over all the dimensions of the input array. The axis may be negative, in which case it counts from the last to the first axis. If axis is a tuple of ints, the operation is performed over multiple axes. :type axis: None, or int, or iterable of ints. :return: The Array representing the requested mean. :rtype: Array """

    axes = _normalise_axis(axis, a)
    if axes is None or len(axes) != 1:
        msg = "This operation is currently limited to a single axis"
        raise AxisSupportError(msg)
    return _Aggregation(a, axes[0],
                        _CountStreamsHandler, _CountMaskedStreamsHandler,
                        np.dtype('i'), {})