code: public static String remove(String str, char remove) {
          if (isEmpty(str) || str.indexOf(remove) == INDEX_NOT_FOUND) {
              return str;
          }
          char[] chars = str.toCharArray();
          int pos = 0;
          for (int i = 0; i < chars.length; i++) {
              if (chars[i] != remove) {
                  chars[pos++] = chars[i];
              }
          }
          return new String(chars, 0, pos);
      }
docs: <p>Removes all occurrences of a character from within the source string.</p>
  
  <p>A <code>null</code> source string will return <code>null</code>.
  An empty ("") source string will return the empty string.</p>
  
  <pre>
  StringUtils.remove(null, *)       = null
  StringUtils.remove("", *)         = ""
  StringUtils.remove("queued", 'u') = "qeed"
  StringUtils.remove("queued", 'z') = "queued"
  </pre>
  
  @param str  the source String to search, may be null
  @param remove  the char to search for and remove, may be null
  @return the substring with the char removed if found,
  <code>null</code> if null String input
  @since 2.1