public @Nullable PsiFileSystemItem innerSingleResolve(final boolean caseSensitive, @NotNull PsiFile containingFile) {
    final ResolveResult[] resolveResults = innerResolve(caseSensitive, containingFile);
    return resolveResults.length == 1 ? (PsiFileSystemItem)resolveResults[0].getElement() : null;
  }
public @Nullable PsiFileSystemItem innerSingleResolve(final boolean caseSensitive, @NotNull PsiFile containingFile)