text: 
  function SigmaLinkService() {
  
    var self = this;
  
    self.execute = function() {};
    self.executeOptions = {};
  
    /**
     * Function to be executed at runtime after sigma has been instantiated. 
     * It allows to set bindings between the different plugin instances
     *
     * @param {Function} link - link function. Is executed with 4 parameters:sigma,
     * sigmaPlugins,the sigma DOM container and some options. The sigma object is 
     * an instance of Sigma. The sigmaPlugins object is an object containing all 
     * the plugins instances that have been initialized with their names as keys.
     * The last argument of the link function will be the executeOption object.
     */
    this.setLink = function(link) {
       self.execute = link;
    };
  
    /**
     * This method allows to store options reference in the service. This option
     * object will be passed to the link function as last argument.
     *
     * @param {Object} linkOptions - Object passed as last argument of the link
     * function
     */
    this.setLinkOptions = function(linkOptions) {
      self.executeOptions = linkOptions;
    };
  
    /**
     * Cleans up Link options.
     */
    this.clearLinkOptions = function() {
      self.executeOptions = {};
    };
  }
  
  angular.module('sigma')
  .service('SigmaLink', SigmaLinkService)
  ;
  