_getOutput(match) {
    var output = (this._found > 1) ? ',\n' : '';

    output += JSON.stringify({
      id: match.hash,
      instances: match.instances.map(instance => {
        return {
          path: this._getRelativePath(instance.filename),
          lines: [instance.start.line, instance.end.line],
          code: this._getLines(instance)
        };
      })
    });

    return output;
  }
Returns the string output to print for the given reporter. The formatted
JSON string contains the number of instances associated with the match and
the files and lines involved.

@private

@param   {Match}  match The inspector match to output
@returns {string} The formatted output