input: Write a function to perform matrix multiplication on two given matrices. The function should take two matrices as input and return the resulting matrix after multiplication.
  assert matrix_multiplication([[1, 2], [3, 4]], [[5, 6], [7, 8]]) == [[19, 22], [43, 50]]
  assert matrix_multiplication([[1, 0], [0, 1]], [[1, 2], [3, 4]]) == [[1, 2], [3, 4]]
  assert matrix_multiplication([[2, 0], [0, 2]], [[3, 4], [3, 4]]) == [[6, 8], [6, 8]]
  assert matrix_multiplication([[1, 2], [3, 4]], [[1, 0], [0, 1]]) == [[1, 2], [3, 4]]
  assert matrix_multiplication([[1, 2, 3], [4, 5, 6]], [[7, 8], [9, 10], [11, 12]]) == [[58, 64], [139, 154]]
output: def matrix_multiplication(A, B):
      result = [[0 for _ in range(len(B[0]))] for _ in range(len(A))]
      for i in range(len(A)):
          for j in range(len(B[0])):
              for k in range(len(B)):
                  result[i][j] += A[i][k] * B[k][j]
      return result