code: function context(schema, value, options) {
  		schema = context.parse(schema)
  		let ret = schema.validate(value, options)
  		context.lastError = schema.lastError
  		context.lastErrorMessage = schema.lastErrorMessage
  		context.lastErrorPath = schema.lastErrorPath
  		return ret
  	}
docs: Validate the given value against the given schema
  @param {*} schema
  @param {*} value The value can be altered by the validation
  @param {Object} [options] Validation options
  @returns {boolean} whether the value is valid or nor
  @throw if the schema is invalid