FindBug Malicious code vulnerability Warnings Solutions

FindBug Malicious code vulnerability Warnings
EI_EXPOSE_REP: May expose internal representation by returning reference to mutable object
EI_EXPOSE_REP2: May expose internal representation by incorporating reference to mutable object

public void setCreatedDate(Date createdDate) {
    this.createdDate = createdDate != null ? (Date) createdDate.clone() : null;
}

public Date getCreatedDate() {
    return createdDate != null ? (Date) createdDate.clone() : null;
}