this method removes a extension from the list of known extensions . concode_field_sep HashMap<String,Icon> resourceCache concode_elem_sep List<String> resourceExtensions concode_elem_sep List<String> resourceLocations concode_field_sep boolean isInCache concode_elem_sep void removeResourceLocation concode_elem_sep java.net.URL lookupIconUrl concode_elem_sep void addResourceExtension concode_elem_sep ImageIcon lookupIconResource concode_elem_sep ImageIcon lookupIconResource concode_elem_sep ImageIcon lookupIconResource concode_elem_sep ImageIcon lookupIconResource concode_elem_sep String toJavaIdentifier concode_elem_sep boolean containsExtension concode_elem_sep void addResourceLocation concode_elem_sep boolean containsLocation