afreechart/src/main/java/org/afree/chart/plot/CategoryPlot.java
/**
     * This method is used to perform argument checking on the list of axis
     * indices passed to mapDatasetToDomainAxes() and mapDatasetToRangeAxes().
     * 
     * @param indices
     *            the list of indices (<code>null</code> permitted).
     */
This method is used to perform argument checking on the list of axis
indices passed to mapDatasetToDomainAxes() and mapDatasetToRangeAxes().

@param indices
the list of indices (null permitted).
This method is used to perform argument checking on the list of axis indices passed to mapDatasetToDomainAxes () and mapDatasetToRangeAxes () . @param indices the list of indices ( null permitted ) .
private void checkAxisIndices(List indices) {
        if (indices == null) {
            return; 
        }
        int count = indices.size();
        if (count == 0) {
            throw new IllegalArgumentException("Empty list not permitted.");
        }
        HashSet set = new HashSet();
        for (int i = 0; i < count; i++) {
            Object item = indices.get(i);
            if (!(item instanceof Integer)) {
                throw new IllegalArgumentException(
                        "Indices must be Integer instances.");
            }
            if (set.contains(item)) {
                throw new IllegalArgumentException("Indices must be unique.");
            }
            set.add(item);
        }
    }
private void checkAxisIndices ( List indices ) { if ( indices == null ) { return ; } int count = indices . size ( ) ; if ( count == 0 ) { throw new IllegalArgumentException ( "Empty list not permitted." ) ; } HashSet set = new HashSet ( ) ; for ( int i = 0 ; i < count ; i ++ ) { Object item = indices . get ( i ) ; if ( ! ( item instanceof Integer ) ) { throw new IllegalArgumentException ( "Indices must be Integer instances." ) ; } if ( set . contains ( item ) ) { throw new IllegalArgumentException ( "Indices must be unique." ) ; } set . add ( item ) ; } }
This method is used to perform argument checking on the list of axis
 indices passed to mapDatasetToDomainAxes() and mapDatasetToRangeAxes().
This method is used to perform argument checking on the list of axis indices passed to mapDatasetToDomainAxes () and mapDatasetToRangeAxes () .
// axisIndices can be: // 1. null; // 2. non-empty, containing only Integer objects that are unique. // OK