Fixed #40. Added support for toSnakeCase function

src/main/java/strman/Strman.java

@@ -1033,6 +1033,16 @@ public abstract class Strman {
         return toDecamelize(value, "-");
     }
 
+    /**
+     * Transform to snake_case.
+     *
+     * @param value The input String
+     * @return String in snake_case.
+     */
+    public static String toSnakeCase(final String value) {
+        return toDecamelize(value, "_");
+    }
+
     public static String decode(final String value, final int digits, final int radix) {
         validate(value, NULL_STRING_PREDICATE, NULL_STRING_MSG_SUPPLIER);
         return Arrays

src/test/java/strman/StrmanTest.java

@@ -776,4 +776,23 @@ public class StrmanTest {
 
         Arrays.stream(fixture).forEach(el -> assertThat(String.format("toKebabCase(%s) should be de-camelize", el), toKebabCase(el), equalTo("de-camelize")));
     }
+
+    @Test
+    public void toSnakeCase_shouldSnakeCaseAString() throws Exception {
+        String[] fixture = {
+                "deCamelize",
+                "de-Camelize",
+                "de camelize",
+                "de  camelize",
+                "de Camelize",
+                "de-camelize",
+                "-de--camelize",
+                "de_camelize",
+                "     de_camelize"
+        };
+
+        Arrays.stream(fixture).forEach(el -> assertThat(String.format("toSnakeCase(%s) should be de_camelize", el), toSnakeCase(el), equalTo("de_camelize")));
+    }
+
+
 }