input: Write a Python function that processes a string comprised of space-separated lowercase characters and returns a dictionary showing the count of the most frequently appearing letters. If there are ties, include all such letters.
  assert character_count('a b b a') == {'a':2,'b': 2}
  assert character_count('a b c a b') == {'a': 2, 'b': 2}
  assert character_count('a b c d g') == {'a': 1, 'b': 1, 'c': 1, 'd': 1, 'g': 1}
  assert character_count('r t g') == {'r': 1,'t': 1,'g': 1}
  assert character_count('b b b b a') == {'b': 4}
  assert character_count('r t g') == {'r': 1,'t': 1,'g': 1}
  assert character_count('') == {}
  assert character_count('a') == {'a': 1}
output: def character_count(s):
      from collections import Counter
      if not s:
          return {}
      count = Counter(s.replace(' ', ''))
      max_count = max(count.values())
      return {char: freq for char, freq in count.items() if freq == max_count}