question: returns the singleton instance of the commonidhandler . concode_field_sep CommonIdHandler instance concode_elem_sep Logger logger concode_elem_sep Map<ProviderName,Map<String,CommonId>> providerCommonIds concode_field_sep void loadMapping concode_elem_sep void setCommonId concode_elem_sep void addCommonId
target: CommonIdHandler function ( ) { if ( instance == null ) { instance = new CommonIdHandler ( ) ; } return instance ; }