/// <summary>
        /// Delete a project configuration entry
        /// </summary>
        ///
        public void DeleteProjectConfiguration(VisualStudioSolutionProjectConfiguration configuration)
        {
            Guard.NotNull(configuration, nameof(configuration));

            _lines.RemoveAt(configuration.LineNumber);

            Load();
        }
        /// <summary>
        /// Add a project configuration entry
        /// </summary>
        ///
        public void AddProjectConfiguration(
            string projectId,
            string projectConfiguration,
            string property,
            string solutionConfiguration)
        {
            Guard.NotNull(projectId, nameof(projectId));
            Guard.NotNull(projectConfiguration, nameof(projectConfiguration));
            Guard.NotNull(property, nameof(property));
            Guard.NotNull(solutionConfiguration, nameof(solutionConfiguration));

            if (ProjectConfigurationsStartLineNumber < 0)
            {
                AddProjectConfigurationsSection();
            }

            int lineNumber = ProjectConfigurationsEndLineNumber;

            var next =
                ProjectConfigurations
                .FirstOrDefault(c =>
                                c.ProjectId == projectId &&
                                string.CompareOrdinal(c.SolutionConfiguration, solutionConfiguration) > 0);

            if (next != null)
            {
                lineNumber = next.LineNumber;
            }

            var prev =
                ProjectConfigurations
                .LastOrDefault(c => c.ProjectId == projectId && c.SolutionConfiguration == solutionConfiguration)
                ?? ProjectConfigurations
                .LastOrDefault(c => c.ProjectId == projectId);

            if (prev != null)
            {
                lineNumber = prev.LineNumber + 1;
            }

            _lines.Insert(
                lineNumber,
                "\t\t" + VisualStudioSolutionProjectConfiguration.Format(
                    projectId,
                    projectConfiguration,
                    property,
                    solutionConfiguration));

            Load();
        }