       WhoWeb.MemberView.parse_member_district("B001300", "House")
       >>> "44"
   """
-  @spec parse_member_district(String.t(), String.t()) :: String.t()
+  @spec parse_member_district(String.t(), String.t()) :: nil | non_neg_integer
   def parse_member_district(member, "Senate"), do: nil
   def parse_member_district(member, "House") do
     at_large =

defmodule WhoWeb.MemberView do
  use WhoWeb, :view

  @doc """

    For Senators, the return value will be nil.

    EX:
      WhoWeb.MemberView.parse_member_district("C001109", "Senate")
      >>> nil

      WhoWeb.MemberView.parse_member_district("C001109", "House")
