remove SteppedRange (#980)

Author: SimonCropp

src/ImageSharp/Common/Extensions/EnumerableExtensions.cs

@@ -11,33 +11,6 @@ namespace SixLabors.ImageSharp.Common
     /// </summary>
     internal static class EnumerableExtensions
     {
-        /// <summary>
-        /// Generates a sequence of integral numbers within a specified range.
-        /// </summary>
-        /// <param name="fromInclusive">
-        /// The start index, inclusive.
-        /// </param>
-        /// <param name="toExclusive">
-        /// The end index, exclusive.
-        /// </param>
-        /// <param name="step">
-        /// The incremental step.
-        /// </param>
-        /// <returns>
-        /// The <see cref="IEnumerable{Int32}"/> that contains a range of sequential integral numbers.
-        /// </returns>
-        public static IEnumerable<int> SteppedRange(int fromInclusive, int toExclusive, int step)
-        {
-            // Borrowed from Enumerable.Range
-            long num = (fromInclusive + toExclusive) - 1L;
-            if ((toExclusive < 0) || (num > 0x7fffffffL))
-            {
-                throw new ArgumentOutOfRangeException(nameof(toExclusive));
-            }
-
-            return RangeIterator(fromInclusive, i => i < toExclusive, step);
-        }
-
         /// <summary>
         /// Generates a sequence of integral numbers within a specified range.
         /// </summary>