Add methods for testing casing of `BaseText`'s charracters

sources/Text/BaseText.uc

@@ -404,6 +404,54 @@ public final function MutableText UpperMutableCopy(
     return textCopy;
 }
 
+/**
+ *  Checks whether all letters in the caller text is in the lower case.
+ *
+ *  @return `true` if there are no characters that qualify as upper case and
+ *      `false` otherwise.
+ */
+public final function bool IsLowerCase()
+{
+    local int       i;
+    local Character nextCharacter;
+
+    if (IsEmpty()) {
+        return true;
+    }
+    for (i = 0; i < GetLength(); i += 1)
+    {
+        nextCharacter = GetCharacter(i);
+        if (_.text.IsUpper(nextCharacter)) {
+            return false;
+        }
+    }
+    return true;
+}
+
+/**
+ *  Checks whether all letters in the caller text is in the lower case.
+ *
+ *  @return `true` if there are no characters that qualify as lower case and
+ *      `false` otherwise.
+ */
+public final function bool IsUpperCase()
+{
+    local int       i;
+    local Character nextCharacter;
+
+    if (IsEmpty()) {
+        return true;
+    }
+    for (i = 0; i < GetLength(); i += 1)
+    {
+        nextCharacter = GetCharacter(i);
+        if (_.text.IsLower(nextCharacter)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 /**
  *  Checks if caller `BaseText` contains a valid name object or not.
  *