input: Write a function to perform matrix multiplication on two given matrices. Return the resulting matrix.
  
  def matrix_multiplication(A, B):  
      rows_A = len(A)  
      cols_A = len(A[0])  
      rows_B = len(B)  
      cols_B = len(B[0])  
      result = [[0 for i in range(cols_B)] for j in range(rows_A)]  
      for i in range(rows_A): 
          for j in range(cols_B): 
              for k in range(cols_A): 
                  result[i][j] += A[i][k] * B[k][j] 
      return result
  
  assert matrix_multiplication([[1, 2], [3, 4]], [[5, 6], [7, 8]]) == [[19, 22], [43, 50]]
  assert matrix_multiplication([[1, 2, 3]], [[4], [5], [6]]) == [[32]]
  assert matrix_multiplication([[1]], [[2]]) == [[2]]
  assert matrix_multiplication([[0, 0], [0, 0]], [[0, 0], [0, 0]]) == [[0, 0], [0, 0]]
  assert matrix_multiplication([[]], [[]]) == [[]]
output: def matrix_multiplication(A, B):  
      rows_A = len(A)  
      cols_A = len(A[0])  
      rows_B = len(B)  
      cols_B = len(B[0])  
      result = [[0 for i in range(cols_B)] for j in range(rows_A)]  
      for i in range(rows_A): 
          for j in range(cols_B): 
              for k in range(cols_A): 
                  result[i][j] += A[i][k] * B[k][j] 
      return result