code: function parseMetadata (source, callback) {
    var i;
    var lines;
    var markerPad = '';
  
    if (!source) return callback(null, {});
    if (source.length === 0) return callback(null, {});
  
    try {
      return callback(null, yaml.load(source) || {});
    }
    catch (error) {
      if (error.problem != null && error.problemMark != null) {
        lines = error.problemMark.buffer.split('\n');
        for (i = 0; i < error.problemMark.column; i++) {
          markerPad += ' ';
        }
        error.message = "YAML: " + error.problem + "\n\n"
          + lines[error.problemMark.line] + "\n" + markerPad + "^\n";
      }
      else {
        error.message = "YAML Parsing error " + error.message;
      }
      return callback(error);
    }
  }
docs: ## Private Methods From the wintersmith markdown plugin.