test: remove unnecessary BIST tests in m-files checking for excessive number of inputs. Remove BIST tests now that interpreter enforces calling function with no more than the number of arguments defined in the function prototype. * makeUniqueStrings.m, makeValidName.m, base64decode.m, base64encode.m, record.m, sound.m, soundsc.m, acosd.m, acot.m, acotd.m, acoth.m, acsc.m, acscd.m, acsch.m, asec.m, asecd.m, asech.m, asind.m, atan2d.m, atand.m, cosd.m, cot.m, cotd.m, coth.m, csc.m, cscd.m, csch.m, sec.m, secd.m, sech.m, sind.m, tand.m, accumdim.m, bincoeff.m, bitget.m, bitset.m, cell2mat.m, circshift.m, cplxpair.m, cumtrapz.m, deg2rad.m, flip.m, fliplr.m, flipud.m, int2str.m, interpft.m, logspace.m, num2str.m, postpad.m, prepad.m, rad2deg.m, rot90.m, rotdim.m, shift.m, subsindex.m, trapz.m, rotx.m, roty.m, rotz.m, getappdata.m, getpixelposition.m, guidata.m, isappdata.m, waitforbuttonpress.m, __gripe_missing_component__.m, bessel.m, hsv2rgb.m, ind2gray.m, rgb2gray.m, rgb2hsv.m, rgbplot.m, fileread.m, javachk.m, usejava.m, findstr.m, genvarname.m, isdir.m, vectorize.m, cond.m, cross.m, duplication_matrix.m, expm.m, isbanded.m, isdefinite.m, isdiag.m, ishermitian.m, issymmetric.m, istril.m, istriu.m, trace.m, vech.m, vecnorm.m, cast.m, citation.m, compare_versions.m, grabcode.m, inputname.m, isfile.m, isfolder.m, ismac.m, ispc.m, isunix.m, list_primes.m, methods.m, news.m, open.m, run.m, swapbytes.m, tar.m, verLessThan.m, zip.m, odeget.m, optimget.m, stemleaf.m, allchild.m, ancestor.m, close.m, groot.m, hgsave.m, isaxes.m, isfigure.m, isgraphics.m, ishandle.m, isprop.m, linkaxes.m, rotate.m, saveas.m, conv.m, poly.m, polyint.m, polyreduce.m, ppval.m, roots.m, addpref.m, getpref.m, ispref.m, rmpref.m, setpref.m, profile.m, profshow.m, powerset.m, autoreg_matrix.m, bartlett.m, blackman.m, detrend.m, fftconv.m, fftfilt.m, fftshift.m, hamming.m, hanning.m, ifftshift.m, sinewave.m, spectral_adf.m, spectral_xdf.m, unwrap.m, nonzeros.m, spconvert.m, sprand.m, sprandn.m, beta.m, betainc.m, betaln.m, cosint.m, expint.m, factorial.m, legendre.m, nchoosek.m, nthroot.m, perms.m, pow2.m, primes.m, reallog.m, realpow.m, realsqrt.m, sinint.m, hankel.m, hilb.m, invhilb.m, magic.m, pascal.m, toeplitz.m, vander.m, wilkinson.m, center.m, corr.m, cov.m, discrete_cdf.m, discrete_inv.m, discrete_pdf.m, empirical_cdf.m, empirical_inv.m, empirical_pdf.m, iqr.m, kendall.m, kurtosis.m, mad.m, meansq.m, median.m, moment.m, prctile.m, quantile.m, range.m, run_count.m, skewness.m, spearman.m, statistics.m, std.m, var.m, base2dec.m, bin2dec.m, blanks.m, dec2base.m, dec2bin.m, dec2hex.m, endsWith.m, erase.m, hex2dec.m, index.m, isletter.m, isstring.m, isstrprop.m, mat2str.m, ostrsplit.m, rindex.m, startsWith.m, strtrunc.m, substr.m, fail.m, addtodate.m, asctime.m, ctime.m, date.m, datestr.m, eomday.m, etime.m, is_leap_year.m, now.m: remove unnecessary BIST tests in m-files checking for excessive number of inputs.

########################################################################
##
## Copyright (C) 1996-2020 The Octave Project Developers
##
## See the file COPYRIGHT.md in the top-level directory of this
## distribution or <https://octave.org/copyright/>.
##
## This file is part of Octave.
##
## Octave is free software: you can redistribute it and/or modify it
## under the terms of the GNU General Public License as published by
## the Free Software Foundation, either version 3 of the License, or
## (at your option) any later version.
##
## Octave is distributed in the hope that it will be useful, but
## WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with Octave; see the file COPYING.  If not, see
## <https://www.gnu.org/licenses/>.
##
########################################################################

## -*- texinfo -*-
## @deftypefn  {} {} is_leap_year ()
## @deftypefnx {} {} is_leap_year (@var{year})
## Return true if @var{year} is a leap year and false otherwise.
##
## If no year is specified, @code{is_leap_year} uses the current year.
##
## For example:
##
## @example
## @group
## is_leap_year (2000)
##    @result{} 1
## @end group
## @end example
## @seealso{weekday, eomday, calendar}
## @end deftypefn

function retval = is_leap_year (year)

  if (nargin == 0)
    t = clock ();
    year = t(1);
  endif

  retval = (rem (year, 4) == 0 & rem (year, 100) != 0) | (rem (year, 400) == 0);

endfunction


%!assert (is_leap_year (2000), true)
%!assert (is_leap_year (1976), true)
%!assert (is_leap_year (1000), false)
%!assert (is_leap_year (1800), false)
%!assert (is_leap_year (1600), true)