This module implements the OAuth behaviour and an oauth2 strategy for DocuSign.
client = DocuSign.OAuth.Impl.client() |> DocuSign.OAuth.Impl.get_token!() {:ok, user_info } = OAuth2.Client.get(client, "/oauth/userinfo")
@type headers() :: [{binary(), binary()}]
@type param() :: binary() | %{required(binary()) => param()} | [param()]
@type params() :: %{required(binary()) => param()} | Keyword.t()