sage declaration statement

 I have a case where I have a SgVarDeclStmt and I want
to insert another statement after that. But, when I use
insertStmtAfter command, it comes back with the following
error and aborted.
   No Control Parent in ComputeControlParent
in computeControlParent() call. 
 If I were to attach this SgVarDeclStmt to the file scope
statement list by insertStmtAfter and then increment to it
by lexNext() call. the attach call on SgVarDeclStmt then
 Is there anyway to make the first case to work besides putting
maybe a dummy statement block around it??