{
  "$schema": "http://json-schema.org/draft-04/schema#",
  "title": "Check if target feature implemented",
  "description": "'There must be 1 or more target relationships associated with an Annotation.' (Section 3.1)",
  "assertionType": "must",
  "expectedResult": "valid",
  "errorMessage": "Error: Annotation has no target relationships - at least 1 is required. (Section 3.1)",
  "type": "object",
  "properties": {
    "target": { "type": ["string", "array", "object"] }
  },
  "required": ["target"]
}