Method retainFrom

corpus/java/training/guava/base/CharMatcher.java:732–734

Returns a string containing all matching characters of a character sequence, in order. For example: CharMatcher.is('a').retainFrom("bazaar") ... returns "aaa".

(CharSequence sequence)

   * ... returns {@code "aaa"}.
   */
  public String retainFrom(CharSequence sequence) {
    return negate().removeFrom(sequence);
  }

  /**
   * Returns a string copy of the input character sequence, with each character that matches this