question: public void copyFrom ( Properties src , boolean shouldResetDefaults ) { Enumeration keys = src . keys ( ) ; while ( keys . hasMoreElements ( ) ) { String key = ( String ) keys . nextElement ( ) ; if ( ! isLegalPropertyKey ( key ) ) throw new IllegalArgumentException ( XSLMessages . createMessage ( XSLTErrorResources . ER_OUTPUT_PROPERTY_NOT_RECOGNIZED , new Object [ ] { key } ) ) ; Object oldValue = m_properties . get ( key ) ; if ( null == oldValue ) { String val = ( String ) src . get ( key ) ; if ( shouldResetDefaults && key . equals ( OutputKeys . METHOD ) ) { setMethodDefaults ( val ) ; } m_properties . put ( key , val ) ; } else if ( key . equals ( OutputKeys . CDATA_SECTION_ELEMENTS ) ) { m_properties . put ( key , ( String ) oldValue + " " + ( String ) src . get ( key ) ) ; } } }
target:  Copy the keys and values from the source to this object.  This will not copy the default values.  This is meant to be used by going from a higher precedence object to a lower precedence object, so that if a key already exists, this method will not reset it.