the fields are given with the `names` arguments,
the corresponding values with the `data` arguments.
If a single field is appended, `names`, `data` and `dtypes` do not have
to be lists but just values.

Parameters
----------
base : array
    Input array to extend.
names : string, sequence
    String or sequence of strings corresponding to the names
    of the new fields.
data : array or sequence of arrays
    Array or sequence of arrays storing the fields to add to the base.
dtypes : sequence of datatypes, optional
    Datatype or sequence of datatypes.
    If None, the datatypes are estimated from the `data`.
fill_value : {float}, optional
    Filling value used to pad missing data on the shorter arrays.
usemask : {False, True}, optional
    Whether to return a masked array or not.
asrecarray : {False, True}, optional
    Whether to return a recarray (MaskedRecords) or not.

z7The number of arrays does not match the number of namesNT)