Insert a line of text in fileeditor without changing the file

like 4 implementations

/**
 * Returns the virtual file corresponding to the specified document.
 *
 * @param document the document for which the virtual file is requested.
 * @return the file, or null if the document wasn't created from a virtual file.
 */
4 implementations
@Nullable
public abstract VirtualFile getFile(@NotNull Document document);