feat(modem): method to configure APN/authentication

reach/client/protocol/modem.go

@@ -0,0 +1,41 @@
+package protocol
+
+type SetModemOptions struct {
+	Apn      *string
+	Type     *string
+	Username *string
+	Password *string
+}
+
+type SetModemOptionsFunc func(opts *SetModemOptions)
+
+func NewSetModemOptions(funcs ...SetModemOptionsFunc) *SetModemOptions {
+	opts := &SetModemOptions{}
+	for _, fn := range funcs {
+		fn(opts)
+	}
+	return opts
+}
+
+func WithApn(value string) SetModemOptionsFunc {
+	return func(opts *SetModemOptions) {
+		opts.Apn = &value
+	}
+}
+
+func WithType(value string) SetModemOptionsFunc {
+	return func(opts *SetModemOptions) {
+		opts.Type = &value
+	}
+}
+
+func WithUsername(value string) SetModemOptionsFunc {
+	return func(opts *SetModemOptions) {
+		opts.Username = &value
+	}
+}
+func WithPassword(value string) SetModemOptionsFunc {
+	return func(opts *SetModemOptions) {
+		opts.Password = &value
+	}
+}