docs: def get_variant_type(variant_source):
      """Try to find out what type of variants that exists in a variant source
      
          Args:
              variant_source (str): Path to variant source
              source_mode (str): 'vcf' or 'gemini'
          
          Returns:
              variant_type (str): 'sv' or 'snv'
      """
      file_type = get_file_type(variant_source)
      variant_type = 'sv'
      if file_type == 'vcf':
          variants = VCF(variant_source)
      elif file_type == 'gemini':
          variants = GeminiQuery(variant_source)
          gemini_query = "SELECT * from variants"
          variants.run(gemini_query)
      # Check 1000 first variants, if anyone is a snv we set the variant_type
      # to 'snv'
      for i,variant in enumerate(variants):
          if file_type == 'vcf':
              if variant.is_snp:
                  variant_type = 'snv'
          elif file_type == 'gemini':
              if variant['type'] == 'snp':
                  variant_type = 'snv'
              
          if i > 1000:
              break
      
      return variant_type