AsMulti casts error to multi error read only interface.

Merge merges multiple Error to single one, but joining all errors together.

New returns NilOrMultiError with provided errors added if not nil.

PrettyPrint prints the same information as multiError.Error() method but with newlines and indentation targeted for humans.

NilOrMultiError type allows combining multiple errors into one.

Error is extended error interface that allows to use returned read-only multi error in more advanced ways.