Whose Uncle?

[Todd Meigs]

At the end of chapter 13, Mason makes a quip on the phrase "Bob's your
Uncle."  Forgive an ignorant American, but what exactly does this mean?  Is
it simply a non-sequator roughly meaning "Whatever happens, happens"?  
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Todd Meigs
It is easy in the world to live after the world's opinion; 
it is easy in solitude to live after our own;
but the great man is he who in the midst of the crowd 
keeps with perfect sweetness 
the independence of solitude.--Emerson
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