Running setEmbeddedCP gives error saying "Error: DERBY_HOME is not set. Please set the DERBY_HOME environment variable"

When derby ran in embedded mode as mentioned in https://db.apache.org/derby/papers/DerbyTut/install_software.html#derby_install, it gives error saying "Error: DERBY_HOME is not set. Please set the DERBY_HOME environment variable". THis can be fixed by creating another path variable "DERBY_HOME" with same value given for DERBY_INSTALL.
Either documentation should be changed to set DERBY_HOME at installation or code should be change to read value from DERBY_INSTALL.