local p = {}
local inspect = require('Dev:Inspect')

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-- Here is the solution:
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-- <onlyinclude><nowiki>
function p.final(frame)
    local clone = mw.clone(frame)
    local metatable = getmetatable(clone.args)

    metatable.__index = nil
    metatable.__pairs = nil

    clone.args.bb = nil
    clone.args.cc = nil

    return '<pre>' .. inspect(clone) .. '</pre>'
end
-- (Ignore this line.)</nowiki></onlyinclude>

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-- Everything below this point is kept for posterity.
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local function makePseudoFrame(frame)
    if type(frame) ~= "table" then
        error("frame must be a table")
    end
 
    local pseudoFrame = {}
 
    for name in pairs(frame) do
        pseudoFrame[name] = function (pseudoFrame, ...)
            return frame[name](frame, ...)
        end
    end
 
    pseudoFrame.args = mw.clone(frame.args)
    pseudoFrame.args.a = nil
 
    function pseudoFrame:getParent()
        if frame:getParent() then
            return makePseudoFrame(frame:getParent())
        end
    end
 
    return pseudoFrame
end

function p.usePseudoFrame(frame)
    local pseudoFrame = makePseudoFrame(frame)

    return '<pre>' .. inspect(pseudoFrame) .. '</pre>'
end

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function p.keepMetatable(frame)
    local clone = mw.clone(frame)

    clone.args.a = nil

    return '<pre>' .. inspect(clone) .. '</pre>'
end

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function p.removeMetatable(frame)
    local clone = mw.clone(frame)

    setmetatable(clone.args, nil)
    clone.args.a = nil

    return '<pre>' .. inspect(clone) .. '</pre>'
end

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function p.reattachMetatable(frame)
    local clone = mw.clone(frame)
    local metatable = getmetatable(clone.args)

    setmetatable(clone.args, nil)
    clone.args.a = nil
    setmetatable(clone.args, metatable)

    return '<pre>' .. inspect(clone) .. '</pre>'
end

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function p.attachMetatableClone(frame)
    local clone = mw.clone(frame)
    local metatable = getmetatable(clone.args)
    local metatableClone = mw.clone(metatable)

    setmetatable(clone.args, nil)
    clone.args.a = nil
    setmetatable(clone.args, metatableClone)

    return '<pre>' .. inspect(clone) .. '</pre>'
end

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function p.removeMetamethod(frame)
    local clone = mw.clone(frame)
    local metatable = getmetatable(clone.args)

    metatable.__index = nil
    clone.args.a = nil

    return '<pre>' .. inspect(clone) .. '</pre>'
end

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local function buildNewMetatable(frame)
    local clone = mw.clone(frame)
    local mt = {}

    function mt.__pairs()
        return next, clone.args
    end

    function mt.__ipairs()
        local function inext(_, i)
            local value = clone.args[i + 1]

            if value then
                return i + 1, value
            end
        end

        return inext, nil, 0
    end

    setmetatable(clone.args, mt)
    clone.args.b = nil
    clone.args[2] = nil

    return clone
end

function p.useNewMetatable(frame)
    local clone = buildNewMetatable(frame)

    return '<pre>' .. inspect(clone) .. '</pre>'
end

return p