def field_should_be_empty(field, scope={})
      in_scope(scope) do
        _field = nice_find_field(field)
        if !(_field.nil? || _field.value.nil? || _field.value.strip == '')
          raise Kelp::Unexpected,
            "Expected field '#{field}' to be empty, but value is '#{_field.value}'"
        end
      end
    end
def field_should_be_empty(field, scope={})
      in_scope(scope) do
        _field = nice_find_field(field)
        if !(_field.nil? || _field.value.nil? || _field.value.strip == '')
          raise Kelp::Unexpected,
            "Expected field '#{field}' to be empty, but value is '#{_field.value}'"
        end
      end
    end
Verify that the given field is empty or nil.

 @param [String] field
   Capybara locator for the field (name, id, or label text)
 @param [Hash] scope
   Scoping keywords as understood by {#in_scope}

 @raise [Kelp::Unexpected]
   If the given field is not empty or nil