Declarative types: Extending requires explicit import statement

package com.guvnor.domain;

import java.math.BigDecimal;

public class Person {

    private BigDecimal salary;

    public BigDecimal getSalary() {
        return salary;
    }

    public void setSalary(BigDecimal salary) {
        this.salary = salary;
    }

}

package com.sample
 
import com.guvnor.domain.Person

declare Person
end

package com.sample
 
import com.guvnor.domain.Person
import com.guvnor.domain.Address

declare Person
end

declare Person2 extends Person
    flange : String
end