def validate(self, model, data_access=None, *, fail_fast=None):
    """Validates a model against the collection of Validations.

    Returns True if all Validations pass, or False if one or more do not.
    """
    if fail_fast is None:
      fail_fast = self.fail_fast

    self.model = model
    self.data_access = data_access
    is_valid = True
    for validation in self.validations:
      if not validation.validate(model, self):
        is_valid = False
        if fail_fast:
          break
    return is_valid
Validates a model against the collection of Validations.

    Returns True if all Validations pass, or False if one or more do not.