/**
 * @function maxCharacter
 * @example - Given a string of characters, return the character that appears the most often. Example: input = "Hello World!" return "l"
 * @param {string} str
 * @param {RegExp} ignorePattern - ignore the char in str that is not required
 * @returns {string} - char
 */
const maxCharacter = (str, ignorePattern) => { // initially it's count only alphabets
  if (typeof str !== 'string') {
    throw new TypeError('Argument should be a string')
  } else if (!str) {
    throw ne