liquibase-core/src/main/java/liquibase/configuration/ConfigurationProperty.java
public void setValue(Object value) {
        if ((value != null) && !type.isAssignableFrom(value.getClass())) {
            throw new UnexpectedLiquibaseException("Property "+name+" on is of type "+type.getSimpleName()+", not "+value.getClass().getSimpleName());
        }

        this.value = value;
        wasOverridden = true;
    }
public void setValue(Object value) {
        if ((value != null) && !type.isAssignableFrom(value.getClass())) {
            throw new UnexpectedLiquibaseException("Property "+name+" on is of type "+type.getSimpleName()+", not "+value.getClass().getSimpleName());
        }

        this.value = value;
        wasOverridden = true;
    }
Overwrites the value currently stored in this property. It he passed type is not compatible with the defined type, an exception is thrown.