code: function sn_api_loc_registerUrlHelperFunction(name, func) {
  	if ( typeof func !== 'function' ) {
  		return;
  	}
  	if ( sn_api_loc_urlHelperFunctions === undefined ) {
  		sn_api_loc_urlHelperFunctions = [];
  	}
  	name = name.replace(/[^0-9a-zA-Z_]/, '');
  	sn_api_loc_urlHelperFunctions.push({name : name, func : func});
  }
docs: Register a custom function to generate URLs with {@link sn.api.loc.locationUrlHelper}.
  
  @param {String} name The name to give the custom function. By convention the function
  names should end with 'URL'.
  @param {Function} func The function to add to sn.api.loc.locationUrlHelper instances.
  @preserve