all = (m, f) => {
  for (const [key, value] of m) {
    if (!f(value, key)) {
      return false;
    }
  }

  return true;
}
Tests whether all key-value pairs pass the test implemented by `f(value, key)`.

@function
@template K
@template V
@param {Map<K,V>} m
@param {function(V,K):boolean} f
@return {boolean}