code: public static String leftPad(String str, int size, char padChar) {
  		return org.apache.commons.lang3.StringUtils.leftPad(str, size, padChar);
  	}
docs: <p>
  Left pad a String with a specified character.
  </p>
  
  <p>
  Pad to a size of {@code size}.
  </p>
  
  <pre>
  StringUtils.leftPad(null, *, *)     = null
  StringUtils.leftPad("", 3, 'z')     = "zzz"
  StringUtils.leftPad("bat", 3, 'z')  = "bat"
  StringUtils.leftPad("bat", 5, 'z')  = "zzbat"
  StringUtils.leftPad("bat", 1, 'z')  = "bat"
  StringUtils.leftPad("bat", -1, 'z') = "bat"
  </pre>
  
  @param str
  the String to pad out, may be null
  @param size
  the size to pad to
  @param padChar
  the character to pad with
  @return left padded String or original String if no padding is necessary,
  {@code null} if null String input
  @since 2.0