Given an array of integers, determine whether the number of occurrences (frequency) of each value in the array is unique. In other words, no two distinct values in the array should appear the same number of times. For example, given the input {1, 2, 2, 1, 1, 3}, the frequency counts are: 1 appears 3 times, 2 appears 2 times, and 3 appears 1 time, which are all unique, so the function should return true. Conversely, for the input {1, 2}, both 1 and 2 appear once, so the function should return false. Requirements: You must solve this problem using a HashMap to count the frequency of each value in a single pass, ensuring an efficient solution.