Don't lock environment for DefaultPlotConfiguration class

[IndrajeetPatil]

Otherwise, if we try to extend this class further (like here), we get the following error:

"cannot add bindings to a locked environment"

[L] signifies that the environment is locked.

library(R6)

Person1 <- R6Class("Person")
rlang::env_print(Person1$new())
#> <environment: 0x000000001967f5b8> [L]
#> Parent: <environment: empty>
#> Class: Person, R6
#> Bindings:
#> * .__enclos_env__: <env>
#> * clone: <fn> [L]

Person2 <- R6Class("Person", lock_objects = FALSE)
rlang::env_print(Person2$new())
#> <environment: 0x000000002026b370>
#> Parent: <environment: empty>
#> Class: Person, R6
#> Bindings:
#> * .__enclos_env__: <env>
#> * clone: <fn> [L]

^{Created on 2022-07-19 by the reprex package (v2.0.1.9000)}