code: public <T> T set( final String propertyName, final T propertyValue )
      {
          m_properties.put( propertyName, propertyValue );
          return propertyValue;
      }
docs: Sets a property.
  
  @param propertyName  name of the property to set
  @param propertyValue value of the property to set
  
  @return the value of property set (fluent api)