From http://stackoverflow.com/questions/32516572/syntax-error-unexpected-expecting
{ 1 => 'a', 2 => 'b' } #=> {1=>"a", 2=>"b"} { :foo => 1, :bar => 2 } #=> {:foo=>1, :bar=>2} { foo: 1, bar: 2 } #=> {:foo=>1, :bar=>2} Hash[21, 22, Hash[23, 24], 25] #=> {21=>22, {23=>24}=>25}