# Eth2 config helpers `preset_loader`: A util to load constants-presets with. See [Constants-presets documentation](../../configs/constants_presets/README.md). Usage: ```python configs_path = 'configs/' ... import preset_loader from eth2spec.phase0 import spec my_presets = preset_loader.load_presets(configs_path, 'mainnet') spec.apply_constants_preset(my_presets) ``` WARNING: this overwrites globals, make sure to prevent accidental collisions with other usage of the same imported specs package.