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: fig.m
    path of file: ./repos/gramm/@gramm
    
    the code of the file until where you have to start completion: function obj = fig(obj,fig)

    
function obj = fig(obj,fig)
% fig Create separate figures according to one factor
%
% Example syntax : gramm_object.fig(variable)
% For each unique value of variable, a new gramm figure will be created,
% containing only the corresponding data. Useful when facet_ generates too
% crowded figures. Warning: the generated gramm figures are independ