Use model.component(<ctag>).mesh(<tag>).create(<ftag>,"CornerRefinement") to decrease the element size defined in the sequence at vertices in 2D and edges in 3D that define a sharp corner. Use 
model.component(<ctag>).mesh(<tag>).feature(<ftag>).create(<ftag1>,"CornerRefinement") to decrease the element size for the feature 
<ftag> that can be any of the types 
Edge, 
FreeQuad, 
FreeTri, or 
FreeTet.
 
    Use model.component(<ctag>).mesh(<tag>).feature(<ftag>).selection() or 
model.component(<ctag>).mesh(<tag>).feature(<ftag>).feature(<ftag1>).selection() to specify the domain selection. If you do not specify any selection, the feature is defined on the entire geometry.