{ # use the propterties from https://react-jsonschema-form.readthedocs.io/en/latest/
"properties": { # (required)
"description": "Select a book.",
"enum": ["Book 1", "Book 2"],
"enumNames": ["Book 1", "Book 2"],
"widget": "MaterialFormSelect",
"description": "The quantity book to order.",
"widget": "MaterialFormNumber",
"minItems": 1, # number of nested fields to load on default
"items": [], # (optional), if provided, it will overwrite the properties