code: function findPropsWithoutDefaultValue (propsNode) {
        return propsNode.value.properties
          .filter(prop => prop.type === 'Property')
          .filter(prop => {
            if (prop.value.type !== 'ObjectExpression') {
              return true
            }
  
            return !propIsRequired(prop) && !propHasDefault(prop)
          })
      }
docs: Finds all props that don't have a default value set
  @param {Property} propsNode - Vue component's "props" node
  @return {boolean}