function parsePointer(pointer) {
    // Converts JSON pointer string into tokens list.

    // Let's split pointer string by tokens' separator character.
    // Also we will reverse resulting array to simplify it's further usage.
    var tokens = pointer.split(TOKENS_SEPARATOR).reverse();

    // Last item in resulting array is always an empty string,
    // we don't need it, let's remove it.
    tokens.pop();

    // Now tokens' array is ready to use, let's return it.
    return tokens;
  }
Returns tokens list for given |pointer|. List is reversed, e.g.
    '/simple/path' -> ['path', 'simple']
@param {!string} pointer JSON pointer string.
@returns {Array} List of tokens.