docs: def format_variant(variant, variant_type='snv'):
      """Convert variant information to a VCF formated string
      
      Args:
          variant(dict)
          variant_type(str)
      
      Returns:
          vcf_variant(str)
      """
      chrom = variant.get('chrom')
      pos = variant.get('start')
      
      ref = variant.get('ref')
      alt = variant.get('alt')
      
      if variant_type == 'sv':
          pos = int((variant['pos_left'] + variant['pos_right'])/2)
          ref = 'N'
          alt = f"<{variant['sv_type']}>"
  
      info = None
      
      info = format_info(variant, variant_type=variant_type)
  
      variant_line = f"{chrom}\t{pos}\t.\t{ref}\t{alt}\t.\t.\t{info}"
      
      return variant_line