@Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;

        DefaultPeptideIon that = (DefaultPeptideIon) o;

        if (charge != that.charge) return false;
        if (Double.compare(that.mass, mass) != 0) return false;
        return !(peptide != null ? !peptide.equals(that.peptide) : that.peptide != null);

    }