code: def read_tx_witnesses(ptr, tx, num_witnesses):
      
      witnesses = []
      for i in xrange(0, num_witnesses):
  
          witness_stack_len = read_var_int(ptr, tx)
          witness_stack = []
  
          for j in xrange(0, witness_stack_len):
  
              stack_item = read_var_string(ptr, tx)
              witness_stack.append(stack_item)
               
          witness_script = btc_witness_script_serialize(witness_stack).decode('hex')
          witnesses.append(witness_script)
  
      return witnesses
docs: Returns an array of witness scripts.
      Each witness will be a bytestring (i.e. encoding the witness script)