input: 
  def matrix_multiplication(A, B):
      """
      This function performs matrix multiplication on two given matrices.
      It takes two matrices A and B as input and returns the resultant matrix.
  
      Example:
      >>> matrix_multiplication([[1, 2], [3, 4]], [[5, 6], [7, 8]])
      [[19, 22], [43, 50]]
      >>> matrix_multiplication([[1, 0], [0, 1]], [[1, 2], [3, 4]])
      [[1, 2], [3, 4]]
      >>> matrix_multiplication([[2, 0], [0, 2]], [[1, 0], [0, 1]])
      [[2, 0], [0, 2]]
      """
      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
  
output:     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