code: @Override
      public String getProperty(final String _name)
      {
          String value = super.getProperty(_name);
          if (value == null && getParentType() != null) {
              value = getParentType().getProperty(_name);
          }
          return value;
      }
docs: Checks if the current type holds the property with the given name. If
  not, the value of the property of the parent type (see
  {@link #getParentType}) is returned (if a parent type exists).
  
  @param _name name of the property (key)
  @return value of the property with the given name / key.
  @see org.efaps.admin.AbstractAdminObject#getProperty