The error type is lost in oneOf

[micronull]

If a field must satisfy multiple rules described using oneOf, we cannot get openapi3.SchemaError types.
The only thing we will get is a string.

components:
  schemas:
    Something:
      type: object
      properties:
        field:
          title: Some field
          oneOf:
            - title: First rule
              type: string
              minLength: 10
              maxLength: 10
            - title: Second rule
              type: string
              minLength: 15
              maxLength: 15

Get the error type errorString.