code: function(key, properties) {
              if(!(/secondaryAxis/.test(key))) {
                  return false;
              }
              if(/secondaryAxisTitle/.test(key)) {
                  return properties[key.replace(/secondaryAxisTitle/, "axisTitleY")];
              }
              return properties[key.replace(/secondaryAxis/, "axisY")];
          }
docs: checks if the given y-axis key is deprecated, and if so returns true if that key's non-deprecated counterpart is set in the properties map, otherwise returns false