core/src/main/java/org/jruby/RubyBasicObject.java
@Override
    public IRubyObject checkStringType() {
        Ruby runtime = metaClass.runtime;
        ThreadContext context = runtime.getCurrentContext();
        BasicObjectSites sites = sites(context);
        return TypeConverter.checkStringType(context, sites.to_str_checked, this);
    }
/** rb_check_string_type
     *
     * Tries to return a coerced string representation of this object,
     * using "to_str". If that returns something other than a String
     * or nil, an empty String will be returned.
     *
     */
rb_check_string_type
Tries to return a coerced string representation of this object,
using "to_str". If that returns something other than a String
or nil, an empty String will be returned.
rb_check_string_type Tries to return a coerced string representation of this object using " to_str " . If that returns something other than a String or nil an empty String will be returned .
@Override
    public IRubyObject checkStringType() {
        Ruby runtime = metaClass.runtime;
        ThreadContext context = runtime.getCurrentContext();
        BasicObjectSites sites = sites(context);
        return TypeConverter.checkStringType(context, sites.to_str_checked, this);
    }
@ Override public IRubyObject checkStringType ( ) { Ruby runtime = metaClass . runtime ; ThreadContext context = runtime . getCurrentContext ( ) ; BasicObjectSites sites = sites ( context ) ; return TypeConverter . checkStringType ( context , sites . to_str_checked , this ) ; }
rb_check_string_type
 Tries to return a coerced string representation of this object,
 using "to_str".
rb_check_string_type Tries to return a coerced string representation of this object using " to_str " .