/// <summary>
        /// Parses entity and it's child entities.
        /// </summary>
        internal void Parse(string text)
        {
            StringReader r = new StringReader(text);

            r.ReadToFirstChar();

            // If starts with ( then multipart/xxx, otherwise normal single part entity
            if (r.StartsWith("("))
            {
                // Entities are (entity1)(entity2)(...) <SP> ContentTypeSubType
                while (r.StartsWith("("))
                {
                    IMAP_BODY_Entity entity = new IMAP_BODY_Entity();
                    entity.Parse(r.ReadParenthesized());
                    entity.m_pParentEntity = this;
                    m_pChildEntities.Add(entity);

                    r.ReadToFirstChar();
                }

                // Read multipart values. (nestedMimeEntries) contentTypeSubMediaType
                string contentTypeSubMediaType = r.ReadWord();

                m_pContentType = MimeUtils.ParseMediaType("multipart/" + contentTypeSubMediaType);
            }
            else
            {
                // Basic fields for non-multipart
                // contentTypeMainMediaType contentTypeSubMediaType (conentTypeParameters) contentID contentDescription contentEncoding contentSize [envelope] [contentLine]

                // Content-Type
                string contentTypeMainMediaType = r.ReadWord();
                string contentTypeSubMediaType  = r.ReadWord();
                if (contentTypeMainMediaType.ToUpper() != "NIL" && contentTypeSubMediaType.ToUpper() != "NIL")
                {
                    m_pContentType =
                        MimeUtils.ParseMediaType(contentTypeMainMediaType + "/" + contentTypeSubMediaType);
                }

                // Content-Type header field parameters
                // Parameters syntax: "name" <SP> "value" <SP> "name" <SP> "value" <SP> ... .
                r.ReadToFirstChar();
                string conentTypeParameters = "NIL";
                if (r.StartsWith("("))
                {
                    conentTypeParameters = r.ReadParenthesized();

                    StringReader contentTypeParamReader =
                        new StringReader(MimeUtils.DecodeWords(conentTypeParameters));
                    List <HeaderFieldParameter> parameters = new List <HeaderFieldParameter>();
                    while (contentTypeParamReader.Available > 0)
                    {
                        string parameterName  = contentTypeParamReader.ReadWord();
                        string parameterValue = contentTypeParamReader.ReadWord();

                        parameters.Add(new HeaderFieldParameter(parameterName, parameterValue));
                    }
                    m_pContentTypeParams = parameters.ToArray();
                }
                else
                {
                    // Skip NIL
                    r.ReadWord();
                }

                // Content-ID:
                string contentID = r.ReadWord();
                if (contentID.ToUpper() != "NIL")
                {
                    m_ContentID = contentID;
                }

                // Content-Description:
                string contentDescription = r.ReadWord();
                if (contentDescription.ToUpper() != "NIL")
                {
                    m_ContentDescription = contentDescription;
                }

                // Content-Transfer-Encoding:
                string contentEncoding = r.ReadWord();
                if (contentEncoding.ToUpper() != "NIL")
                {
                    m_ContentEncoding = MimeUtils.ParseContentTransferEncoding(contentEncoding);
                }

                // Content Encoded data size in bytes
                string contentSize = r.ReadWord();
                if (contentSize.ToUpper() != "NIL")
                {
                    m_ContentSize = Convert.ToInt32(contentSize);
                }

                // Only for ContentType message/rfc822
                if (ContentType == MediaType_enum.Message_rfc822)
                {
                    r.ReadToFirstChar();

                    // envelope
                    if (r.StartsWith("("))
                    {
                        m_pEnvelope = new IMAP_Envelope();
                        m_pEnvelope.Parse(r.ReadParenthesized());
                    }
                    else
                    {
                        // Skip NIL, ENVELOPE wasn't included
                        r.ReadWord();
                    }

                    // TODO:
                    // BODYSTRUCTURE

                    // contentLine
                }

                // Only for ContentType text/xxx
                if (contentTypeMainMediaType.ToLower() == "text")
                {
                    // contentLine
                    string contentLines = r.ReadWord();
                    if (contentLines.ToUpper() != "NIL")
                    {
                        m_ContentLines = Convert.ToInt32(contentLines);
                    }
                }
            }
        }