code: public MetaProperty getMetaProperty(String name) {
          MetaProperty mp = this.expandoProperties.get(name);
          if (mp != null) return mp;
          return super.getMetaProperty(name);
      }
docs: Looks up an existing MetaProperty by name
  
  @param name The name of the MetaProperty
  @return The MetaProperty or null if it doesn't exist