base_collection	=> $collection_object
  base_dir	        => $collection_directory
  type		=> $name_of_this_linker_type

  my $self = shift;
  my %params = @_;

  unless ((exists $params{corpus_name}) && (exists $params{link_prob})) {
    croak "ErdosRenyi->create_corpus requires the following arguments:
	corpus_name => name of new corpus
	link_prob   => probability of linking any two nodes\n";
  }
  my $download_dir = $self->{download_base} . "/" . $params{corpus_name};
  my $corpus_dir = $self->{corpus_data} . "/" . $params{corpus_name};
  my $doc_dir = $self->{base_collection}->{docs_dir};
  my $N = $self->{base_collection}->{size};

  $self->prepare_directories($params{corpus_name});

  open (LINKS, ">$corpus_dir/$params{corpus_name}.links");

  for my $i (0..$N-2) {
    for my $j ($i+1..$N-1) {
      if ((-e "$doc_dir/synth.$i") &&
	  (-e "$doc_dir/synth.$j") &&
	  (random_uniform() > $params{link_prob})) {
	print LINKS "synth.$i synth.$j\n";
	print LINKS "synth.$j synth.$i\n";
      }
    }
  }

  close LINKS;

  # Now, generate the html docs and the url2file map, which is
  #  needed for indexing the corpus.
  my $url2file = $self->create_html_no_anchors 
    (src_doc_dir => $self->{base_collection}->{docs_dir},
     html_dir => 
       "$download_dir/www.$params{corpus_name}.com",
        links_file  => "$corpus_dir/$params{corpus_name}.links",
        base_url    => "www.$params{corpus_name}.com");

  my $uniq_file = $self->{base_dir} . "/$params{corpus_name}.download.uniq";
  open (LINKSUNIQ, ">$uniq_file") ||
    croak "Cannot create file $uniq_file\n";

  for (my $i = 0; $i < @$url2file; $i++) {
    print LINKSUNIQ $url2file->[$i] . "\n";
  }

  close (LINKSUNIQ);

  # Call the superclass
  $self->SUPER::create_corpus($params{corpus_name}, $self->{base_dir});

  my $class = shift;

  my %params = @_;
  # Instantiate our base class/create representation
  $params{model_name} = "ErdosRenyi";
  my $self = $class->new_linker(%params);

  return $self;