title: How can I check if a procedure exists in a package?
body: <p>I have packages with procedures, which are used in many places and in some places I need slightly different procedures, e.g. updating one more column.</p>
  
  <p>I thought that I could create an extra package, which would contain some but not all of the procedures.</p>
  
  <p>Is there any way to check in an <code>if</code> statement directly in scripts, that if there does not exist procedure in the extra package, to fall back on the standard package?</p>