@spec format(pdu :: SMPPEX.Pdu.t(), indent :: String.t(), pad :: String.t()) ::
  iolist()

Forms an iolist containing colored Pdu dump.

indent is the string prepended to each line of the dump (" " by default). pad is the string prepended to nested lines of the dump together with indent. The default is "".

Example

iex> pdu = SMPPEX.Pdu.Factory.submit_sm({"from", 1, 1}, {"to", 1, 1}, "hello")

Then pdu |> SMPPEX.Pdu.PP.format |> IO.puts() will print:

pdu: submit_sm
  command_id: 4
  command_status: 0 (ok)
  sequence_number: 0
mandatory fields:
  dest_addr_npi: 1
  dest_addr_ton: 1
  destination_addr: "to"
  registered_delivery: 0
  short_message: "hello"
  source_addr: "from"
  source_addr_npi: 1
  source_addr_ton: 1
optional fields: []