src/main/java/org/helm/notation2/parser/notation/HELM2Notation.java
@JsonIgnore
  public PolymerNotation getPolymerNotation(String id) {
    for (PolymerNotation polymer : listOfPolymers) {
      if (polymer.getPolymerID().getId().equals(id)) {
        return polymer;
      }
    }

    return null;
  }
@JsonIgnore
  public PolymerNotation getPolymerNotation(String id) {
    for (PolymerNotation polymer : listOfPolymers) {
      if (polymer.getPolymerID().getId().equals(id)) {
        return polymer;
      }
    }

    return null;
  }
method to get a specific polymer by its id

@param id polymer id
@return polymer