code: function (contextModel, properties, parentContext) {
  
                  if (!(contextModel || properties && _.size(properties))) {
                      // no contextModel OR no properties or empty object passed
                      return this.root();
                  }
  
                  parentContext = parentContext || this.root();
                  return parentContext.getContext(contextModel, properties);
  
              }
docs: *
  Returns the context for a properties object
  @param {js.data.Model} contextModel
  @param {Object} properties
  @param {js.data.DataSource.Context} [parentContext]
  @return {js.data.DataSource.Context}