RNAPRoductAdaptor: move object creation from sth to own function

This will facilitate reusability because this bit of code will be the
same regardless of the SQL query invoked by the sth.

modules/Bio/EnsEMBL/DBSQL/RNAProductAdaptor.pm

@@ -301,7 +301,6 @@ SQL
 
 sub _fetch_direct_query {
   my ($self, $where_args) = @_;
-  my @return_data;
 
   my $rp_created_date =
     $self->db()->dbc()->from_date_to_seconds('created_date');
@@ -317,6 +316,25 @@ sub _fetch_direct_query {
   my $sth = $self->prepare($sql);
   $sth->bind_param(1, $where_args->[1], $where_args->[2]);
   $sth->execute();
+  my $results = $self->_obj_from_sth($sth);
+  $sth->finish();
+
+  return $results;
+}
+
+
+# _obj_from_sth
+#  Arg [1]    : DBI statement handle
+#  Description: PRIVATE internal method shared between public SQL-query
+#               methods in order to avoid duplication of object-creation
+#               logic.
+#  Returntype : ArrayRef of either Bio::EnsEMBL::RNAProducts or undefs
+#  Exceptions : throws if rnaproduct type is absent or unknown
+#  Caller     : internal
+#  Status     : At Risk (In Development)
+sub _obj_from_sth {
+  my ($self, $sth) = @_;
+  my @return_data;
 
   my $sql_data = $sth->fetchall_arrayref();
   my $transcript_adaptor = $self->db()->get_TranscriptAdaptor();
@@ -350,8 +368,6 @@ sub _fetch_direct_query {
     push @return_data, $rnaproduct;
   }
 
-  $sth->finish();
-
   return \@return_data;
 }