driver-core/src/main/com/mongodb/MongoCompressor.java
public <T> T getPropertyNonNull(final String key, final T defaultValue) {
        T value = getProperty(key, defaultValue);
        if (value == null) {
            throw new IllegalArgumentException();
        }
        return value;
    }
public <T> T getPropertyNonNull(final String key, final T defaultValue) {
        T value = getProperty(key, defaultValue);
        if (value == null) {
            throw new IllegalArgumentException();
        }
        return value;
    }
Gets the property with the given key.

@param key the key
@param defaultValue the default value
@param <T> the property value type
@return the property value, or the default value if the property is not defined
@throws IllegalArgumentException if the value and default value are null
@since 3.7