code: function getExclusions(astNode) {
      var comments = parseASTComments(astNode),
          commandCodes = CommandRegistry.getAllCommandCodes(),
          params,
          exclusions = {};
  
      _.forEach(comments, function(comment) {
          if(comment.indexOf(EXCLUSION_KEYWORD) !== -1) {
              params = comment.match(/\[.*\]/g);
              if(params) {
                  // Replace all single quotes with double quotes to be able to JSON parse them
                  _.forEach(JSON.parse(params[0].replace(/'/g, '\"')), function(exclusion) {
                      if(commandCodes.indexOf(exclusion) !== -1) {
                          exclusions[exclusion] = true;
                      } else {
                          logger.warn('Encountered an unknown exclusion: %s', exclusion);
                      }
                  });
              }
  
              // Exclude all mutations when none are specifically excluded
              if(_.keys(exclusions).length === 0){
                  _.forEach(commandCodes, function(code) {
                      exclusions[code] = true;
                  });
              }
          }
      });
  
      return exclusions;
  }
docs: Get the specific exclusions for a given [astNode], if there are any.
  @param {object} astNode the AST node from which comments should be retrieved
  @returns {object} a list of mutation codes [key] that are excluded. [value] is always true