---Declare table as a base class
---@param cls table class table
---@param o table class instance table
---@return table o base class instance table
function Base(cls, o)
    cls.__index = cls
    o = o or {}
    setmetatable(o, cls)
    return o
end

---Declare table as a derived class
---@param cls table class table
---@param base table base class table
---@param o table class instance table
---@return table o derived class instance table
function Inherit(cls, base, o)
    cls.__index = cls
    setmetatable(cls, {__index = base})
    o = base:new(o)
    setmetatable(o, cls)
    return o
end