question: public static String maxCommonPrefix ( String one , String two ) { final int minLength = Math . min ( one . length ( ) , two . length ( ) ) ; final StringBuilder sb = new StringBuilder ( minLength ) ; for ( int pos = 0 ; pos < minLength ; pos ++ ) { final char currentChar = one . charAt ( pos ) ; if ( currentChar != two . charAt ( pos ) ) { break ; } sb . append ( currentChar ) ; } return sb . toString ( ) ; }
target:  Returns max common prefix of two strings.