Repository: Azure/azure-sdk-for-net
File: sdk/core/Azure.Core/src/ContentType.cs (C#)

Code before:
        /// </summary>
        public static ContentType TextPlain { get; } = new ContentType("text/plain");

        /// <summary>
        /// Creates an instance of <see cref="ContentType"/>.
        /// </summary>
        /// <param name="contentType">The content type string.</param>
        public ContentType(string contentType)
        {
            Argument.AssertNotNull(contentType, nameof(contentType));

            _contentType = contentType;
        }

        /// <summary>
        /// Creates an instance of <see cref="ContentType"/>.
        /// </summary>
        /// <param name="contentType">The content type string.</param>
        public static implicit operator ContentType(string contentType)
        {
            if (contentType is null)
            {
                return default;
            }
            return new ContentType(contentType);
        }

        /// <inheritdoc />
        public bool Equals(ContentType other)
        {
            return string.Equals(_contentType, other._contentType, StringComparison.Ordinal);
        }

        /// <inheritdoc />
        public bool Equals(string? other)
            => string.Equals(_contentType, other, StringComparison.Ordinal);

        /// <inheritdoc />
        public override bool Equals(object? obj)
            => (obj is ContentType other && Equals(other)) ||
               (obj is string str && str.Equals(_contentType, StringComparison.Ordinal));

        /// <inheritdoc />
        public override int GetHashCode()
            => _contentType?.GetHashCode() ?? 0;

        /// <summary>
        /// Compares equality of two <see cref="ContentType"/> instances.
        /// </summary>
        /// <param name="left">The method to compare.</param>
        /// <param name="right">The method to compare against.</param>

Review comment (suggestion):
```suggestion

            return new ContentType(contentType);
```

Code after:
        /// </summary>
        public static ContentType TextPlain { get; } = new ContentType("text/plain");

        /// <summary>
        /// Creates an instance of <see cref="ContentType"/>.
        /// </summary>
        /// <param name="contentType">The content type string.</param>
        public ContentType(string contentType)
        {
            Argument.AssertNotNull(contentType, nameof(contentType));

            _contentType = contentType;
        }

        /// <summary>
        /// Creates an instance of <see cref="ContentType"/>.
        /// </summary>
        /// <param name="contentType">The content type string.</param>
        public static implicit operator ContentType(string? contentType)
        {
            if (contentType is null)
            {
                return default;
            }

            return new ContentType(contentType);
        }

        /// <inheritdoc />
        public bool Equals(ContentType other)
        {
            return string.Equals(_contentType, other._contentType, StringComparison.Ordinal);
        }

        /// <inheritdoc />
        public bool Equals(string? other)
            => string.Equals(_contentType, other, StringComparison.Ordinal);

        /// <inheritdoc />
        public override bool Equals(object? obj)
            => (obj is ContentType other && Equals(other)) ||
               (obj is string str && str.Equals(_contentType, StringComparison.Ordinal));

        /// <inheritdoc />
        public override int GetHashCode()
            => _contentType?.GetHashCode() ?? 0;

        /// <summary>
        /// Compares equality of two <see cref="ContentType"/> instances.
        /// </summary>
        /// <param name="left">The method to compare.</param>