code: public static String join( Collection col, char sep )
  	{
  		if( col.isEmpty() )
  		{
  			return "";
  		}
  		StringBuffer buffer = new StringBuffer();
  		boolean first = true; 
  		for (Object o : col)
  		{
  			if( first )
  			{
  				first = false;
  			}
  			else
  			{
  				buffer.append( sep );
  			}
  			buffer.append( o.toString() );
  		}
  		return buffer.toString();
  	}
docs: Join the <tt>String</tt> representations of a collection of objects, with the specified
  separator.
  
  @param col the col
  @param sep the sep
  @return  newly created .