code: def build(self, schema: Schema) -> Mapping[str, Any]:
          
          fields = list(self.iter_fields(schema))
  
          properties = {
              field.name: self.build_parameter(field)
              for name, field in fields
          }
  
          result = dict(
              type="object",
              properties=properties,
          )
  
          required_fields = [
              name
              for name, field in fields
              if field.required and not field.allow_none
          ]
  
          if required_fields:
              result["required"] = required_fields
  
          return result
docs: Build JSON schema from a marshmallow schema.