code: function tryEval (func, context) {
      try {
          return func(context);
      } catch(e) {
          log('warn',
              `Property function in layer '${context.layers[context.layers.length-1]}' failed with\n`,
              `error ${e.stack}\n`,
              `function '${func.source}'\n`,
              context.feature, context);
      }
  }
docs: eval property function with try/catch