code: def filter_pem(data):
      '''Processes the bytes for PEM certificates.
  
      Returns:
          ``set`` containing each certificate
      '''
      assert isinstance(data, bytes), 'Expect bytes. Got {}.'.format(type(data))
      certs = set()
      new_list = []
      in_pem_block = False
  
      for line in re.split(br'[\r\n]+', data):
          if line == b'-----BEGIN CERTIFICATE-----':
              assert not in_pem_block
              in_pem_block = True
          elif line == b'-----END CERTIFICATE-----':
              assert in_pem_block
              in_pem_block = False
  
              content = b''.join(new_list)
              content = rewrap_bytes(content)
  
              certs.add(b'-----BEGIN CERTIFICATE-----\n' +
                        content +
                        b'\n-----END CERTIFICATE-----\n')
  
              new_list = []
          elif in_pem_block:
              new_list.append(line)
  
      return certf filter_pem(data):
      '''Processes the bytes for PEM certificates.
  
      Returns:
          ``set`` containing each certificate
      '''
      assert isinstance(data, bytes), 'Expect bytes. Got {}.'.format(type(data))
      certs = set()
      new_list = []
      in_pem_block = False
  
      for line in re.split(br'[\r\n]+', data):
          if line == b'-----BEGIN CERTIFICATE-----':
              assert not in_pem_block
              in_pem_block = True
          elif line == b'-----END CERTIFICATE-----':
              assert in_pem_block
              in_pem_block = False
  
              content = b''.join(new_list)
              content = rewrap_bytes(content)
  
              certs.add(b'-----BEGIN CERTIFICATE-----\n' +
                        content +
                        b'\n-----END CERTIFICATE-----\n')
  
              new_list = []
          elif in_pem_block:
              new_list.append(line)
  
      return certs
docs: Processes the bytes for PEM certificates.
  
      Returns:
          ``set`` containing each certificate