question: private static Properties copyProperties ( Properties input ) { if ( input == null ) { return null ; } Properties output = new Properties ( ) ; @ SuppressWarnings ( "unchecked" ) Enumeration < String > propertyNames = ( Enumeration < String > ) input . propertyNames ( ) ; while ( propertyNames . hasMoreElements ( ) ) { String propertyName = propertyNames . nextElement ( ) ; output . setProperty ( propertyName , input . getProperty ( propertyName ) ) ; } return output ; }
target:  Creates a copy of the given properties instance.