README.md in rdf-3.0.13 vs README.md in rdf-3.1.0

@@ -27,11 +27,12 @@
 * Implements basic graph pattern (BGP) query evaluation.
 * Plays nice with others: entirely contained in the `RDF` module, and does
   not modify any of Ruby's core classes or standard library.
 * Based entirely on Ruby's autoloading, meaning that you can generally make
   use of any one part of the library without needing to load up the rest.
-* Compatible with Ruby Ruby >= 2.2.2, Rubinius and JRuby 9.0+.
+* Compatible with Ruby Ruby >= 2.4, Rubinius and JRuby 9.0+.
+  * Note, changes in mapping hashes to keyword arguments for Ruby 2.7+ may require that arguments be passed more explicitly, especially when the first argument is a Hash and there are optional keyword arguments. In this case, Hash argument may need to be explicitly included within `{}` and the optional keyword arguments may need to be specified using `**{}` if there are no keyword arguments.
 * Performs auto-detection of input to select appropriate Reader class if one
   cannot be determined from file characteristics.
 
 ### HTTP requests
 
@@ -187,10 +188,10 @@
       person: {
         RDF.type  => FOAF.Person,
         FOAF.name => :name,
         FOAF.mbox => :email,
       }
-    })
+    }, **{})
     
     query.execute(graph) do |solution|
       puts "name=#{solution.name} email=#{solution.email}"
     end
 
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