input: Write a python function to count the occurrences of each character in a list of strings.
  assert count_characters(['apple', 'banana', 'carrot']) == {'a': 3, 'p': 2, 'l': 1, 'e': 1, 'b': 1, 'n': 2, 'c': 1, 'r': 2, 'o': 1, 't': 1}
  assert count_characters(['hello', 'world']) == {'h': 1, 'e': 1, 'l': 3, 'o': 2, 'w': 1, 'r': 1, 'd': 1}
  assert count_characters(['abcd', 'efgh', 'ijkl']) == {'a': 1, 'b': 1, 'c': 1, 'd': 1, 'e': 1, 'f': 1, 'g': 1, 'h': 1, 'i': 1, 'j': 1, 'k': 1, 'l': 1}
output: def count_characters(strings):
      char_count = {}
      for string in strings:
          for char in string:
              if char in char_count:
                  char_count[char] += 1
              else:
                  char_count[char] = 1
      return char_count