Title   : new
 Usage   : $seq    = Bio::Seq::RichSeq->new( -seq => 'ATGGGGGTGGTGGTACCCT',
                                             -id  => 'human_id',
				             -accession_number => 'AL000012',
				            );

 Function: Returns a new seq object from
           basic constructors, being a string for the sequence
           and strings for id and accession_number
 Returns : a new Bio::Seq::RichSeq object

 Title   : division
 Usage   : $obj->division($newval)
 Function: 
 Returns : value of division
 Args    : newvalue (optional)

 Title   : molecule
 Usage   : $obj->molecule($newval)
 Function: 
 Returns : type of molecule (DNA, mRNA)
 Args    : newvalue (optional)

 Title   : add_date
 Usage   : $self->add_date($datestr)
 Function: adds one or more dates

           This implementation stores dates as keyed annotation, the
           key being 'date_changed'. You can take advantage of this
           fact when accessing the annotation collection directly.

 Example :
 Returns : 
 Args    : a date string or an array of such strings

 Title   : get_dates
 Usage   : my @dates = $seq->get_dates;
 Function: Get the dates of the sequence (usually, when it was created and
           changed.
 Returns : an array of date strings
 Args    :

 Title   : pid
 Usage   : my $pid = $seq->pid();
 Function: Get (and set, depending on the implementation) the PID property
           for the sequence.
 Returns : a string
 Args    :

 Title   : accession
 Usage   : $obj->accession($newval)
 Function: Whilst the underlying sequence object does not 
           have an accession, so we need one here.

           In this implementation this is merely a synonym for
           accession_number().
 Example : 
 Returns : value of accession
 Args    : newvalue (optional)

 Title   : add_secondary_accession
 Usage   : $self->add_domment($ref)
 Function: adds a secondary_accession

           This implementation stores secondary accession numbers as
           keyed annotation, the key being 'secondary_accession'. You
           can take advantage of this fact when accessing the
           annotation collection directly.

 Example :
 Returns : 
 Args    : a string or an array of strings

 Title   : get_secondary_accessions
 Usage   : my @acc = $seq->get_secondary_accessions();
 Function: Get the secondary accession numbers as strings.
 Returns : An array of strings
 Args    : none

 Title   : seq_version
 Usage   : $obj->seq_version($newval)
 Function: Get/set the sequence version
 Returns : value of seq_version (a scalar)
 Args    : on set, new value (a scalar or undef, optional)
 Note    : this differs from Bio::PrimarySeq version() in that this explicitly
           refers to the sequence record version one would find in a typical
           sequence file.

 Title   : add_keyword
 Usage   : $obj->add_keyword($newval)
 Function: Add a new keyword to the annotation of the sequence.

           This implementation stores keywords as keyed annotation,
           the key being 'keyword'. You can take advantage of this
           fact when accessing the annotation collection directly.

 Returns : 
 Args    : value to be added (optional) (a string)

 Title   : get_keywords
 Usage   : $obj->get_keywords($newval)
 Function: Get the keywords for this sequence as an array of strings.
 Returns : an array of strings
 Args    :

 Title   : _add_annotation_value
 Usage   :
 Function: Adds a value to the annotation collection under the specified
           key. Note that this is not a public method.
 Returns : 
 Args    : key (a string), value(s) (one or more scalars)

 Title   : _get_annotation_values
 Usage   :
 Function: Gets the values of a specific annotation as identified by the
           key from the annotation collection. Note that this is not a
           public method.
 Example :
 Returns : an array of strings
 Args    : the key (a string)