code: public static String replaceAll(final String str, final String target, final String replacement) {
          return replaceAll(str, 0, target, replacement);
      }
docs: <p>
  Replaces all occurrences of a String within another String.
  </p>
  
  <p>
  A {@code null} reference passed to this method is a no-op.
  </p>
  
  <pre>
  N.replaceAll(null, *, *)        = null
  N.replaceAll("", *, *)          = ""
  N.replaceAll("any", null, *)    = "any"
  N.replaceAll("any", *, null)    = "any"
  N.replaceAll("any", "", *)      = "any"
  N.replaceAll("aba", "a", null)  = "aba"
  N.replaceAll("aba", "a", "")    = "b"
  N.replaceAll("aba", "a", "z")   = "zbz"
  </pre>
  
  @see #replaceAll(String text, String searchString, String replacement,
  int max)
  @param str
  text to search and replace in, may be null
  @param target
  the String to search for, may be null
  @param replacement
  the String to replace it with, may be null
  @return the text with any replacements processed, {@code null} if null
  String input