It might be required for you to import the package if you encounter any issues (like casting an Array), so better be safe than sorry and add the import.
import crafttweaker.entity.Attribute;

ZenGetter	GetterMethod	Rückgabetyp
ZenGetter name	GetterMethod getName()	Rückgabetyp string
ZenGetter defaultValue	GetterMethod getDefaultValue()	Rückgabetyp double
ZenGetter shouldWatch	GetterMethod getShouldWatch()	Rückgabetyp boolean
ZenGetter parent	GetterMethod getParent()	Rückgabetyp IEntityAttribute

• double clampValue(double Value) → Does something...