code: function min (o, func) {
                      if(!o || typeof o !== 'object') return o;
                      if(libs.object.size(o) === 0) return;
  
                      if(!(func instanceof Function)) func = undefined;
  
                      if(typeof o !== 'object') return o;
                      var min, minValue;
  
                      if(!func) {
                          min = libs.object.first(o);
                          libs.object.each(o, 1, function (item) {
                              if(item <= min) min = item;
                          });
                      }
                      else {
                          min      = libs.object.first(o);
                          minValue = func.call(min, min);
  
                          libs.object.each(o, 1, function (item) {
                              var value = func.call(item, item);
                              if(value <= minValue) {
                                  min      = item;
                                  minValue = value;
                              }
                          });
                      }
                      return min;
                  }
docs: Returns the minimum item in the object.
  @param {Object} o The object to operate on.
  @param {Function=} func If passed, the function will be invoked for each item in the object collection.
  @return {*} The minimum item in the object collection.