public static StringBuilder appendKeyValue(final StringBuilder sb, final String key,
    final Object value) {
    return appendKeyValue(sb, key, value, DEFAULT_SEPARATOR, DEFAULT_KEYVALUE_SEPARATOR);
  }
Append to a StringBuilder a key/value. Uses default separators.
@param sb    StringBuilder to use
@param key   Key to append.
@param value Value to append.
@return Passed <code>sb</code> populated with key/value.
hbase-common/src/main/java/org/apache/hadoop/hbase/util/Strings.java