/**
 * Processes a LaTeX string by replacing instances of `\\frac` with `\\frac{}{}`.
 *
 * This function takes a LaTeX string and replaces all occurrences of `\\frac` with `\\frac{}{}`.
 * It does not handle the numerator and denominator separately or check if they are already enclosed in curly braces.
 *
 * Args:
 *     string (str): The LaTeX string to be processed.
 *
 * Returns:
 *     str: The processed LaTeX string with `\\frac` replaced by `\\frac{}{}`.
 */
You should write code starting with:
def _fix_fracs(string: str) -> str:
    pass

