v0.16.4

What's Changed

• Accept mixed time column in IAMC data by @meksor in #251
• Harmonize all string-representations of objects by @danielhuppmann in #252
• Fix run.optimization..list() listing items from all runs. by @meksor in #249
• update RunMetaDescriptor.__set__ typehint to use Mapping by @meksor in #248

Full Changelog: v0.16.3...v0.16.4