Special environments like the global environment have their own
"global" for the global environment.
"empty" for the empty environment.
"base" for the base package environment (the last environment on the search path).
env is the namespace of the package "pkg".
The empty string
env_label() is exactly like
env_name() but returns the memory
address of anonymous environments as fallback.
# Some environments have specific names: env_name(global_env())#>  "global"env_name(ns_env("rlang"))#>  "namespace:rlang"# Anonymous environments don't have names but are labelled by their # address in memory: env_name(env())#>  ""env_label(env())#>  "0x4eb3750"