class AttributeRankingImpl extends RankingImpl {

    protected final WeakReference<Column> column;

    public AttributeRankingImpl(Column column) {
        super();
        this.column = new WeakReference<>(column);
    }

    @Override
    public Number getMinValue(Graph graph) {
        return getIndex(graph).getMinValue(column.get());
    }

    @Override
    public Number getMaxValue(Graph graph) {
        return getIndex(graph).getMaxValue(column.get());
    }

    private Index<Element> getIndex(Graph graph) {
        return graph.getModel().getElementIndex(column.get().getTable(), graph.getView());
    }

    @Override
    public Number getValue(Element element, Graph graph) {
        return (Number) element.getAttribute(column.get(), graph.getView());
    }

    @Override
    public boolean isValid(Graph graph) {
        Column col = column.get();
        if (col != null && col.getIndex() != -1) {
            return col.isNumber() && !col.isArray();
        }
        return false;
    }

    @Override
    public int hashCode() {<FILL_FUNCTION_BODY>}

    @Override
    public boolean equals(Object obj) {
        if (obj == null) {
            return false;
        }
        if (getClass() != obj.getClass()) {
            return false;
        }
        final AttributeRankingImpl other = (AttributeRankingImpl) obj;
        return Objects.equals(this.column, other.column);
    }

    @Override
    public Column getColumn() {
        return column.get();
    }
}

        int hash = 3;
        hash = 67 * hash + (this.column != null ? this.column.hashCode() : 0);
        return hash;
    
<methods>public non-sealed void <init>() ,public Column getColumn() ,public org.gephi.appearance.api.Interpolator getInterpolator() ,public float getNormalizedValue(Element, Graph) ,public abstract boolean isValid(Graph) ,public float normalize(java.lang.Number, org.gephi.appearance.api.Interpolator, java.lang.Number, java.lang.Number) ,public void setInterpolator(org.gephi.appearance.api.Interpolator) <variables>public static org.gephi.appearance.api.Interpolator DEFAULT_INTERPOLATOR,protected org.gephi.appearance.api.Interpolator interpolator