code: protected void setDirty(boolean d) {
          boolean old = isDirty();
          this.dirty = d;
          firePropertyChange("dirty", old, isDirty());
          if (isDirty()) {
              clearCache();
          }
      }
docs: Sets the dirty bit. If true, then the painter is considered dirty, and the cache
  will be cleared. This property is bound.
  
  @param d whether this <code>Painter</code> is dirty.