[Nikita S. Doroshenko]

I would like to SetJustifyH "CENTER" all ObjectiveTrackerBlocks and remove all "Dashes" as well. I'm talking about Blocks that contains information about Quests you currently track:
(Sorry for different language on screenshot)


Files that respond to this frames locates in Interface\AddOns\Blizzard_ObjectiveTracker\ folder.
There are lots of files in this folder, but I think most relevant is this: Blizzard_ObjectiveTracker.lua (link to wowprogramming.com)

There are lot's of complex functions that I had never worked before. For example:

function DEFAULT_OBJECTIVE_TRACKER_MODULE:SetHeader(block, text, animateReason)
    block.module = self;
    block.isHeader = true;
    block.Text:SetText(text);
    block.animateReason = animateReason or 0;
    self.Header = block;
end

I tried to investigate more information about this functions and how they works, and for me (person who never programmed before, it's pretty hard to instantly understand them, but i would like).
On Hooking Functions Guide I read that it's possible to hook this strange functions. This Guide gives this example:

--[[Functions called using the object calling syntax, object:method(...), can also be hooked; one simply has to remember that the construct is merely syntactic sugar for objec*****thod(object, ...);. To hook a function that was originally declared as:]]
function AnAddon.Module:FuncName(arg1)
  -- Things happen here...
end
--[[We store the original function and replace it with a hook:]]
local original_AnAddon_Module_FuncName = AnAddon.Module.FuncName;
function AnAddon.Module:FuncName(...)
  local arg1 = ...; -- Use the vararg expression in case the function signature changes
  if type(arg1) == "number" and arg1 > 0 then
    -- Call the original function; because of object calling syntax, 
    --   pass self as the first argument.
    return original_AnAddon_Module_FuncName(self, ...);
  end
end
--[[The example hook above will only allow the original function to be called if the first argument is a strictly positive number.]]

According to this example, i tryed to hook Blizzards function "DEFAULT_OBJECTIVE_TRACKER_MODULE:SetHeader" with this code:

local DEFAULT_OBJECTIVE_TRACKER_MODULE_SET_HEADER = DEFAULT_OBJECTIVE_TRACKER_MODULE.SetHeader
function DEFAULT_OBJECTIVE_TRACKER_MODULE:SetHeader(...)
    print("TEST")
    return DEFAULT_OBJECTIVE_TRACKER_MODULE_SET_HEADER(self, ...);
end

But it looks like that i'm doing something wrong. I don't get any lua errors, but no print("TEST") as well, so it's not hooked.
I will very appreciate if you could help me with example of how can i hook this complex functions or with advice or ideas how can i SetJustifyH("CENTER") and remove Dash without hooking this crazy functions (Names of ObjectiveTrackerBlocks are dynamic: example on screenshot)