code: private boolean parseVariant(SequenceLocation sequenceLocation, String line) {
          boolean validVariant;
          String[] fields = line.split("\t", -1);
          String mutationCds = fields[17];
  
          if (mutationCds.contains(">")) {
              validVariant = parseSnv(mutationCds, sequenceLocation);
              if (!validVariant) {
                  invalidSubstitutionLines++;
              }
          } else if (mutationCds.contains("del")) {
              validVariant = parseDeletion(mutationCds, sequenceLocation);
              if (!validVariant) {
                  invalidDeletionLines++;
              }
          } else if (mutationCds.contains("ins")) {
              validVariant = parseInsertion(mutationCds, sequenceLocation);
              if (!validVariant) {
                  invalidInsertionLines++;
              }
          } else if (mutationCds.contains("dup")) {
              validVariant = parseDuplication(mutationCds);
              if (!validVariant) {
                  invalidDuplicationLines++;
              }
          } else {
              validVariant = false;
              invalidMutationCDSOtherReason++;
          }
  
          return validVariant;
      }
docs: Check whether the variant is valid and parse it.
  
  @return true if valid mutation, false otherwise