add a new declaration to the current scope using a unique prefix and return the prefix . this is useful when one just wants to add a decl and does n't want to have to deal with creating unique prefixes . if the namespace name is already declared and in scope , then the previously declared prefix is returned . concode_field_sep String NS_PREFIX_PREFIX concode_elem_sep List<List<NSDecl>> stack concode_elem_sep List<NSDecl> top concode_elem_sep int size concode_elem_sep int nsPrefixCount concode_field_sep void pop concode_elem_sep String getPrefix concode_elem_sep void push concode_elem_sep String getURI