How to initialize as .set ?
 

I can find certain special pattern for initializing a .set . I was able to understand it, but how dimensionedScalar can be initialized as .set for example as below how to initialize as .set

dimensionedScalar Cvm
(
"Cvm",
dimless,
transportProperties.lookup("Cvm")
);

and

dimensionedScalar C1
(
dimensionedScalar::lookupOrAddToDict
(
"C1",
kEpsilonDict,
1.44
)
);