customize-set-variable is an interactive autoloaded compiled Lisp function in `
(customize-set-variable VARIABLE VALUE &optional COMMENT)
Set the default for VARIABLE to VALUE, and return VALUE.
VALUE is a Lisp object.
If VARIABLE has a `custom-set' property, that is used for setting
VARIABLE, otherwise `set-default' is used.
If VARIABLE has a `variable-interactive' property, that is used as if
it were the arg to `interactive' (which see) to interactively read the value.
If VARIABLE has a `custom-type' property, it must be a widget and the
`:prompt-value' property of that widget will be used for reading the value.
If given a prefix (or a COMMENT argument), also prompt for a comment.