You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: bluewhitered.m
    path of file: ./repos/FEMLab/FEMLab/functions/+util
    
    the code of the file until where you have to start completion: function newmap = bluewhitered(m)
%BLUEWHITERED   Blue, white, and red color map.

    
function newmap = bluewhitered(m)
%BLUEWHITERED   Blue, white, and red color map.
%   BLUEWHITERED(M) returns an M-by-3 matrix containing a blue to white
%   to red colormap, with white corresponding to the CAXIS value closest
%   to zero.  This colormap is most useful for images and surface plots
%   with positive and negative values.  BLUEWHITERED, by itself, is the
%   same length as the current colormap.
%
%   Examples:
%   ------------------------------
%   figure
%   imagesc(peaks(250));
%   colormap(bluewhitered(256)), colorbar
%
%   figure
%   imagesc(peaks(250), [0 8])
%   colormap(bluewhitered), colorbar
%
%   figure
%   imagesc(peaks(250), [-6 0])
%   colormap(bluewhitered), colorbar
%
%   figure
%   surf(peaks)
%   colormap(bluewhitered)
%   axis tight
%
%   See also HSV, HOT, COOL, BONE, COPPER, PINK, FLAG, 
%   COLORMAP, RGBPLOT.


if nargin < 1
   m = size(get(gcf,'colormap'),1);
end