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: indBalls_l0.m
    path of file: ./repos/ForBES/library
    
    the code of the file until where you have to start completion: %INDBALLS_L0 Indicator function of the product of (nonconvex) L0 balls.
%
%   INDBALLS_L0(m, N) builds the product of L0 balls of dime
    
function of the product of (nonconvex) L0 balls.
%
%   INDBALLS_L0(m, N) builds the product of L0 balls of dimension m with radius N.
% 
%   INDBALLS_L0(m, N, T) same as the above, but the L0 balls are
%   intersected with [-T, T] boxes.

function obj = indBalls_l0(m, N, T)
    if nargin < 3
        T = inf;
    end