def each
            return enum_for(:each) unless block_given? 
            io = nil
            if @is_gz
                infile = open(@file)
                io = Zlib::GzipReader.new(infile) 
            else
                io =  File.open(@file)
            end
            
            header = BioVcf::VcfHeader.new 
            io.each_line do |line|  
                line.chomp!
                if line =~ /^##fileformat=/
                    header.add(line)  
                    next
                end
                if line =~ /^#/
                    header.add(line)
                    next
                end
                fields = BioVcf::VcfLine.parse(line)
                rec    = BioVcf::VcfRecord.new(fields,header)
                yield rec
            end
        end
def each
            return enum_for(:each) unless block_given? 
            io = nil
            if @is_gz
                infile = open(@file)
                io = Zlib::GzipReader.new(infile) 
            else
                io =  File.open(@file)
            end
            
            header = BioVcf::VcfHeader.new 
            io.each_line do |line|  
                line.chomp!
                if line =~ /^##fileformat=/
                    header.add(line)  
                    next
                end
                if line =~ /^#/
                    header.add(line)
                    next
                end
                fields = BioVcf::VcfLine.parse(line)
                rec    = BioVcf::VcfRecord.new(fields,header)
                yield rec
            end
        end
Returns an enum that can be used as an iterator.