impl missing Checkable trait method (paritytech#973)

primitives/self-contained/Cargo.toml

@@ -28,3 +28,6 @@ std = [
 	"frame-support/std",
 	"sp-runtime/std",
 ]
+try-runtime = [
+	"sp-runtime/try-runtime",
+]

primitives/self-contained/src/unchecked_extrinsic.rs

@@ -117,6 +117,38 @@ where
 			})
 		}
 	}
+
+	#[cfg(feature = "try-runtime")]
+	fn unchecked_into_checked_i_know_what_i_am_doing(
+		self,
+		lookup: &Lookup,
+	) -> Result<Self::Checked, TransactionValidityError> {
+		if self.0.function.is_self_contained() {
+			match self.0.function.check_self_contained() {
+				Some(signed_info) => Ok(CheckedExtrinsic {
+					signed: match signed_info {
+						Ok(info) => CheckedSignature::SelfContained(info),
+						_ => CheckedSignature::Unsigned,
+					},
+					function: self.0.function,
+				}),
+				None => Ok(CheckedExtrinsic {
+					signed: CheckedSignature::Unsigned,
+					function: self.0.function,
+				}),
+			}
+		} else {
+			let checked =
+				Checkable::<Lookup>::unchecked_into_checked_i_know_what_i_am_doing(self.0, lookup)?;
+			Ok(CheckedExtrinsic {
+				signed: match checked.signed {
+					Some((id, extra)) => CheckedSignature::Signed(id, extra),
+					None => CheckedSignature::Unsigned,
+				},
+				function: checked.function,
+			})
+		}
+	}
 }
 
 impl<Address, Call, Signature, Extra> ExtrinsicMetadata