feat: ToBuilder() BarFillerBuilder

Author: vbauerster

bar_filler_bar.go

@@ -133,6 +133,10 @@ func (s BarStyleComposer) Reverse() BarStyleComposer {
 	return s
 }
 
+func (s BarStyleComposer) ToBuilder() BarFillerBuilder {
+	return s
+}
+
 func (s BarStyleComposer) Build() BarFiller {
 	bf := &barFiller{metas: s.metas}
 	bf.components[iLbound] = component{

bar_filler_spinner.go

@@ -57,6 +57,10 @@ func (s SpinnerStyleComposer) Meta(fn func(string) string) SpinnerStyleComposer
 	return s
 }
 
+func (s SpinnerStyleComposer) ToBuilder() BarFillerBuilder {
+	return s
+}
+
 func (s SpinnerStyleComposer) Build() BarFiller {
 	sf := &spinnerFiller{frames: s.frames}
 	switch s.position {