input: Write a python function to count the occurrence of a DNA sequence within itself using Biopython.
  assert count_dna_sequence("ATGGGCTAG") == 1
  assert count_dna_sequence("ATGGGCTAGATGGGCTAG") == 2
  assert count_dna_sequence("ATGGGCTAGATGGGCTAGATGGGCTAG") == 3
output: from Bio.Seq import Seq
  
  def count_dna_sequence(dna_sequence):
      sequence = Seq(dna_sequence)
      return sequence.count(dna_sequence)