code: def is_pkcs12(data):
      
      if isinstance(data, bytes):
          tlv = Tlv(data)
          if tlv.tag == 0x30:
              header = Tlv(tlv.value)
              return header.tag == 0x02 and header.value == b'\x03'
          return False
      else:
          return False
docs: Tries to identify a PKCS12 container.
      The PFX PDU version is assumed to be v3.
      See: https://tools.ietf.org/html/rfc7292.