if ( project.getProperty(this.ifExpression) == null) { return false; }
return CastUtil.getBoolean(project.getProperty(this.ifExpression));
	public boolean isActive( Project project ) {		if (this.unlessExpression != null) {			if (project.getProperty(this.unlessExpression) != null) {				return false;			}		}		if (this.ifExpression != null ) {			if ( project.getProperty(this.ifExpression) == null) {				return false;			}		}		return true;	}