wanted patch types vs actual patch types openfoam
 

Hi to all,
I am trying to define a GeometricFiled<Type> within my codes.So,Iam trying to understand the constructors of the class.
If anyone can help me to understand following,I am very grateful.

GeometricField (const IOobject &, const Mesh &, const dimensioned< Type > &, const wordList &wantedPatchTypes, const wordList &actualPatchTypes=wordList())

Thanks.