/**
* Replace given characters in a given string builder.
* The number of characters to replace has to match to number of
* characters serving as a replacement.
*
* @param sb string builder containing a string to be modified
* @param from characters to replaced
* @param to replacement characters
* @return original string builder with replaced characters.
*/
public static StringBuilder replace(StringBuilder sb, CharSequence from, CharSequence to) {
assert from.length() == to.length();
for (int i=0; i<sb.length(); i++)
for (int j=0; j<from.length(); j++)
if (sb.charAt(i)==from.charAt(j)) sb.setCharAt(i, to.charAt(j));
return sb;
}
