@Override
    public boolean equals(Object o) {

        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }

        In that = (In) o;

        if (expression != null ? !expression.equals(that.expression) : that.expression != null) {
            return false;
        }
        if (sourceId != null ? !sourceId.equals(that.sourceId) : that.sourceId != null) {
            return false;
        }

        return true;
    }
In condition {@link Expression} checking events from Table or Window
modules/siddhi-query-api/src/main/java/io/siddhi/query/api/expression/condition/In.java