* @param {string} safeVal Known value that was previously returned by this
* function, if none, pass empty string.
* @param {string} newVal New value that may have to be trimmed down.
* @param {number} byteLimit Number of bytes the value may be in size.
* @param {string} safeVal Known value that was previously returned by this
* function, if none, pass empty string.
* @param {string} newVal New value that may have to be trimmed down.
* @param {number} byteLimit Number of bytes the value may be in size.