style: fix Bad Smells in spoon.support.util.ImmutableMapImpl

[MartinWitt]

Repairing Code Style Issues

UnnecessaryToStringCall

The toString() method is not needed in cases the underlying method handles the conversion. Also calling toString() on a String is redundant. Removing them simplifies the code.

Changes:

• Remove redudant toString() call in parent.toString()

[SirYwell]

Looks good.

As a side note, do you think it would make sense to write transformations that would transform code from

sb.append(a);
sb.append(b);

to

sb.append(a).append(b);

?
(probably with better formatting)

[MartinWitt]

As a side note, do you think it would make sense to write transformations that would transform code from

Writing formatting transformation is a possibility, for sure. But I'm unsure if this field is already solved by spotless and other tools. Also, formatting is very opinionated and not as strict as bad smells. So, I skipped this until now.