Return to Revisions

#Java 8, 131 129 bytes

a->{java.util.Set r=new java.util.HashSet();for(String s:a)if("a->{jv.utilSe r=nwHsh();fog:\"cd}".contains(s))r.add(s);return r;}

Explanation:

Try it here.

a->{                    // Method with String-array parameter and Set return-type
  java.util.Set r=new java.util.HashSet();
                        //  The result Set
  for(String s:a)       //  Loop over the input String-array
    if("a->{jv.utilSe r=nwHsh();fog:\"cd}".contains(s))
                        //   If the current character is part of the source-code:
      r.add(s);         //    Add it to the Set
                        //  End of loop (implicit / single-line body)
  return r;             //  Return the result-Set
}                       // End of method