How could I make this code much neater?

[jeAz_]

So, I currently have the following code written.

A.CreateDruidMana = function(f, unit)
 local DruidMana = CreateFrame("StatusBar", "DruidMana", f);
 DruidMana:SetStatusBarTexture(POWER_BAR);
 DruidMana:SetOrientation("VERTICAL");
 
 DruidMana.background = DruidMana:CreateTexture(nil, "BACKGROUND");
 DruidMana.background:SetTexture(BACKDROP);
 DruidMana.background:SetVertexColor(0.1, 0.1, 0.1, 1);
 DruidMana.background:SetSize(10, f:GetHeight());
 DruidMana.background:SetPoint("LEFT", f, "RIGHT", 2, 0);
 
 DruidMana:SetPoint("TOPLEFT", DruidMana.background, "TOPLEFT", 2, -2);
 DruidMana:SetPoint("BOTTOMRIGHT", DruidMana.background, "BOTTOMRIGHT", -2, 2);
 
 local bg = DruidMana:CreateTexture(nil, "BACKGROUND");
 bg:SetAllPoints(true);
 bg:SetTexture(BACKDROP);
 
 A.AddOptions(DruidMana, "frequentUpdates");
 bg.multiplier = 0.2;
 
 f.DruidMana = DruidMana;
 f.DruidMana.bg = bg;
end

The reason that I created another texture called Background is to create a outer background like the following image:



However, I would like to Create "DruidMana" as a "Frame" rather than "StatusBar" and create "StatusBar" called "Bar" which becomes child object of "DruidMana" then Set Backdrop for "DruidMana" which I would like to use as outer frame instead of using texture called "Background".

Which would become:

local DruidMana = CreateFrame("Frame", "DruidMana", f);
local Bar = CreateFrame("StatusBar", nil, DruidMana);
local bg = Bar:CreateTexture(nil, "BACKGROUND");

I actually tried it, but it was not possible to set "DruidMana" as "f.DruidMana" since "DruidMana" was set to "Frame", not "StatusBar".

In addition to that even if I set "Bar" as "f.DruidMana", "DruidMana" does not hide on shape shift...

Could I please get an advice regarding this?