code: function ManyToOne(elements) {
      return function (targetObject, propertyKey) {
          var entityMetadata = targetObject;
          if (!entityMetadata.manyToOneMap) {
              entityMetadata.manyToOneMap = {};
          }
          entityMetadata.manyToOneMap[propertyKey] = elements;
      };
  }
docs: Specifies a single-valued association to another entity class that has many-to-one multiplicity.
  
  http://docs.oracle.com/javaee/7/api/javax/persistence/ManyToOne.html
  
  @param elements
  @returns {function(any, string)}
  @constructor