/**
 * Get the count of the longest repeating streak of `character` in `value`.
 *
 * @param {string} value
 *   Content to search in.
 * @param {string} character
 *   Single character to look for.
 * @returns {number}
 *   Count of most frequent adjacent `character`s in `value`.
 */
export function longestStreak(value: string, character: string): number