/// <summary>
    /// Implements Import-Csv command.
    /// </summary>
    [Cmdlet(VerbsData.Import, "Csv", DefaultParameterSetName = "DelimiterPath", HelpUri = "https://go.microsoft.com/fwlink/?LinkID=113341")]
    public sealed
    class
    ImportCsvCommand : PSCmdlet
    {
        #region Command Line Parameters

        /// <summary>
        /// Property that sets delimiter.
        /// </summary>
        [Parameter(ParameterSetName = "DelimiterPath", Position = 1)]
        [Parameter(ParameterSetName = "DelimiterLiteralPath", Position = 1)]
        [ValidateNotNull]
        public char Delimiter { get; set; }

        /// <summary>
        /// Mandatory file name to read from.
        /// </summary>
        [Parameter(ParameterSetName = "DelimiterPath", Position = 0, Mandatory = true, ValueFromPipeline = true, ValueFromPipelineByPropertyName = true)]
        [Parameter(ParameterSetName = "CulturePath", Position = 0, Mandatory = true, ValueFromPipeline = true, ValueFromPipelineByPropertyName = true)]
        [ValidateNotNullOrEmpty]
        public String[] Path
        {
            get
            {
                return _paths;
            }
            set
            {
                _paths = value;
                _specifiedPath = true;
            }
        }
        private string[] _paths;
        private bool _specifiedPath = false;

        /// <summary>
        /// The literal path of the mandatory file name to read from.
        /// </summary>
        [Parameter(ParameterSetName = "DelimiterLiteralPath", Mandatory = true, ValueFromPipelineByPropertyName = true)]
        [Parameter(ParameterSetName = "CultureLiteralPath", Mandatory = true, ValueFromPipelineByPropertyName = true)]
        [ValidateNotNullOrEmpty]
        [Alias("PSPath", "LP")]
        [SuppressMessage("Microsoft.Performance", "CA1819:PropertiesShouldNotReturnArrays")]
        public string[] LiteralPath
        {
            get
            {
                return _paths;
            }
            set
            {
                _paths = value;
                _isLiteralPath = true;
            }
        }
        private bool _isLiteralPath = false;

        /// <summary>
        /// Property that sets UseCulture parameter.
        /// </summary>
        [Parameter(ParameterSetName = "CulturePath", Mandatory = true)]
        [Parameter(ParameterSetName = "CultureLiteralPath", Mandatory = true)]
        [ValidateNotNull]
        public SwitchParameter UseCulture
        {
            get
            {
                return _useculture;
            }
            set
            {
                _useculture = value;
            }
        }
        private bool _useculture;

        ///<summary>
        /// Header property to customize the names.
        ///</summary>
        [Parameter(Mandatory = false)]
        [ValidateNotNullOrEmpty]
        [SuppressMessage("Microsoft.Performance", "CA1819:PropertiesShouldNotReturnArrays")]
        public string[] Header { get; set; }

        /// <summary>
        /// Encoding optional flag.
        /// </summary>
        [Parameter()]
        [ArgumentToEncodingTransformationAttribute()]
        [ArgumentEncodingCompletionsAttribute]
        [ValidateNotNullOrEmpty]
        public Encoding Encoding { get; set; } = ClrFacade.GetDefaultEncoding();

        /// <summary>
        /// Avoid writing out duplicate warning messages when there are one or more unspecified names.
        /// </summary>
        private bool _alreadyWarnedUnspecifiedNames = false;

        #endregion Command Line Parameters