/// <summary>
 /// Get specified species observation field.
 /// </summary>
 /// <param name="speciesObservationFields">Species observation fields.</param>
 /// <param name="speciesObservationClass">Web service request context.</param>
 /// <param name="speciesObservationProperty">Species observation search criteria.</param>
 /// <returns>Specified species observation field.</returns>
 public static WebSpeciesObservationField GetField(this List <WebSpeciesObservationField> speciesObservationFields,
                                                   SpeciesObservationClassId speciesObservationClass,
                                                   SpeciesObservationPropertyId speciesObservationProperty)
 {
     return(speciesObservationFields.GetField(speciesObservationClass.ToString(),
                                              speciesObservationProperty.ToString()));
 }
        /// <summary>
        /// Add a field to the species observation.
        /// </summary>
        /// <param name="speciesObservation">The species observation.</param>
        /// <param name="speciesObservationClassId">Species observation class id.</param>
        /// <param name="speciesObservationPropertyId">Species observation property id.</param>
        /// <param name="value">A Double value.</param>
        public static void AddField(this WebSpeciesObservation speciesObservation,
                                    SpeciesObservationClassId speciesObservationClassId,
                                    SpeciesObservationPropertyId speciesObservationPropertyId,
                                    Double value)
        {
            WebSpeciesObservationField field;

            if (speciesObservation.Fields.IsNull())
            {
                speciesObservation.Fields = new List <WebSpeciesObservationField>();
            }

            field = new WebSpeciesObservationField();
            field.ClassIdentifier    = speciesObservationClassId.ToString();
            field.PropertyIdentifier = speciesObservationPropertyId.ToString();
            field.Type  = WebDataType.Float64;
            field.Value = value.WebToString();
            speciesObservation.Fields.Add(field);
        }