code: function wrap1(val, opts, key) {
    switch(getType(val, opts, key)) {
    case 'B': return {'B': val};
    case 'BS': return {'BS': val};
    case 'N': return {'N': val.toString()};
    case 'NS': return {'NS': eachToString(val)};
    case 'S': return {'S': val.toString()};
    case 'SS': return {'SS': eachToString(val)};
    case 'BOOL': return {'BOOL': val ? true: false};
    case 'L': return {'L': val.map(function(obj){ return wrap1(obj, opts); })};
    case 'M': return {'M': wrap(val, opts)};
    case 'NULL': return {'NULL': true};
    default: return;
    }
  }
docs: Wrap a single value into DynamoDB's AttributeValue.
  @param {String|Number|Array}  val The value to wrap.
  @return {Object} DynamoDB AttributeValue.