//fmt.Printf("Operand: %v\n", p.input)
	if len(p.input) == 0 {
		p.errorf("empty operand: cannot happen")
		return
	}
	// General address (with a few exceptions) looks like
	//	$sym±offset(SB)(reg)(index*scale)
	// Exceptions are:
	//
	//	R1
	//	offset
	//	$offset
	// Every piece is optional, so we scan left to right and what
	// we discover tells us where we are.

	// Prefix: $.

	}

	fErr := cmd.Execute()
	output := out.String()

	if c.expectedException {
		if fErr == nil {
			t.Fatalf("Wanted an exception, "+
				"didn't get one, output was %q", output)
		}
	} else {
		if fErr != nil {
			t.Fatalf("Unwanted exception: %v", fErr)
		}
	}

	if c.expectedOutput != "" && c.expectedOutput != output {
		assert.Equal(t, c.expectedOutput, output)

// used to e.g. quickly compare objects or check whether
// the content of an object has changed.
//
// In general, an S3 ETag is an MD5 checksum of the object
// content. However, there are many exceptions to this rule.
//
// # Single-part Upload
//
// In case of a basic single-part PUT operation - without server
// side encryption or object compression - the ETag of an object
// is its content MD5.
//

	}
	for _, file := range nextFiles {
		required = append(required, fileFeatures(file, true)...)
	}
	exception := fileFeatures(filepath.Join(testenv.GOROOT(t), "api/except.txt"), false)

	if exitCode == 1 {
		t.Errorf("API database problems found")
	}
	if !compareAPI(bw, features, required, exception) {
		t.Errorf("API differences found")
	}
}

// export emits the exported package features.

	}

	if c.wantException {
		if fErr == nil {
			t.Fatalf("Wanted an exception for 'istioctl %s', didn't get one, output was %q",
				strings.Join(c.args, " "), output)
		}
	} else {
		if fErr != nil {
			t.Fatalf("Unwanted exception for 'istioctl %s': %v", strings.Join(c.args, " "), fErr)
		}
	}
}

declarations and definitions. These may then be referred to from Go
code as though they were defined in the package "C". All names
declared in the preamble may be used, even if they start with a
lower-case letter. Exception: static variables in the preamble may
not be referenced from Go code; static functions are permitted.

See $GOROOT/cmd/cgo/internal/teststdio and $GOROOT/misc/cgo/gmp for examples. See