code: func NotEqual(left, right OperandBuilder) ConditionBuilder {
  	return ConditionBuilder{
  		operandList: []OperandBuilder{left, right},
  		mode:        notEqualCond,
  	}
  }
docs: // NotEqual returns a ConditionBuilder representing the not equal clause of the
  // two argument OperandBuilders. The resulting ConditionBuilder can be used as a
  // part of other Condition Expressions or as an argument to the WithCondition()
  // method for the Builder struct.
  //
  // Example:
  //
  //     // condition represents the not equal clause of the item attribute "foo"
  //     // and the value 5
  //     condition := expression.NotEqual(expression.Name("foo"), expression.Value(5))
  //
  //     // Used in another Condition Expression
  //     anotherCondition := expression.Not(condition)
  //     // Used to make an Builder
  //     builder := expression.NewBuilder().WithCondition(condition)
  //
  // Expression Equivalent:
  //
  //     expression.NotEqual(expression.Name("foo"), expression.Value(5))
  //     // Let :five be an ExpressionAttributeValue representing the value 5
  //     "foo <> :five"