Recently I had to export some PL SQL packages from an Oracle databse into flat files.
Before I was always exporting them using the "Export..." function available from the context menu of a package.
These exports were either incomplete because I did not tick the option "Export dependencies" in the export dialog or if I did tick the option, the tool exported also scripts to create objects like referenced tables and sequences.
Both options were not satisfying and led to me having to carefully manually edit the exported script files. This would mean to execute something on the target system without having tested it. In summary I did not feel comfortable and save with this export dialog.
Therefore I searched for another option and it is pretty obvious. Right click on a package and select "Package-Spezifikation und Body speichern...". This option will be named different depending on your SQL Developers language settings.