public static PsiFile getContainingFile(@NotNull ASTNode thisElement) {
    FileASTNode node = findFileElement(thisElement);
    PsiElement psi = node == null ? null : node.getPsi();
    if (psi == null || psi instanceof PsiFile) return (PsiFile)psi;
    throw new AssertionError("Invalid PSI " + psi + " of " + psi.getClass() + " for AST " + node + " of " + node.getClass());
  }
public static PsiFile getContainingFile(@NotNull ASTNode thisElement)